Slow Cooker French Onion Soup

This is a post that almost didn't happen. You see, after making caramelized onions in the slow cooker for my previous post, I couldn't wait to turn them into an easy batch of French Onion Soup. Seemed like an automatic win. So, I made a batch of soup using the same ingredients traditionally used, and the results were, well, BLAH.  Mediocre flavor. Sigh. Back to the drawing board. Fortunately this doesn't happen too often, but sometimes I can't get a recipe right and I abandon it rather than sharing something disappointing on my blog. I mean, after all, it has to be yummy, right? Well, my first try at the soup was definitely not worthy of The Yummy Life.

I put the soup in the fridge wondering if I could figure out a way to improve on the flavor. Got up the next day and tasted it again, and it magically tasted so much better. I'd read in Cooks Illustrated's French Onion Soup recipe that the flavor improved on the 2nd or 3rd day--they were right! I also remembered reading in their Slow Cooker Cookbook that you can sometimes add soy sauce to soups and stews to give them a richer, deeper flavor. Who knew? Worth a try. That worked, too!  Those two simple changes, letting the flavors meld for a day and adding a little soy sauce, gave this soup the flavor boost it needed. Whew! I'm loving the rich, hearty flavor of this recipe now, and it's so, so easy!

It's definitely sloooooooooooow cooking. Although this recipe is super easy and requires very little actual preparation time, it does take a long time to cook. The sliced onions need to hang out in the slow cooker for 12-14 hours. Once they're cooked, you add the remaining ingredients and let it simmer in the slow cooker for another 1-2 hours or on the stove-top for 30 minutes. Then it needs to go into the fridge until the next day. Yes, it's easy, but it does require planning and preparing ahead. What's so convenient, though, is that once the soup is made and in the fridge, you can prepare a bowl of this soup in just a few minutes. Just heat the soup (microwave or stove top), top it with toasted bread and cheese, and put it under the broiler for 3-4 minutes. Since the soup is prepared in advance, that makes it a great option for a quick bowl of soup when you get home from a busy day, or when you're feeding guests. 

Nutritional Information (for one 10-oz serving topped with bread and cheese): 289 calories, 16g fat, 22.7g carbs, 4.1g fiber, 5.6g sugar, 17.3g protein; Weight Watchers PointPlus: 8

Step-by-step photos for making
Slow Cooker French Onion Soup 

Step 1. Assemble these ingredients:

• yellow onions
• olive oil
• dry sherry
• chicken broth
• beef broth
• reduced sodium soy sauce
• fresh thyme
• bay leaf
• ground black pepper
• salt to taste
• bread slices (not soft sandwich bread)
• Parmesan cheese (optional, but I like the flavor boost)
• Gruyere cheese (may substitute Swiss; or, for stringier melted cheese use half shredded mozzarella)

Step 2. Slice and caramelize the onions and olive oil in the slow cooker on high for 12-14 hours. For more detailed instructions and photos, see my previous post:  Slow Cooker Caramelized Onions.

view on Amazon:  my Programmable Crock Pot 
(rated #1 by Cooks Illustrated)

Step 3. Add the sherry to the caramelized onions in the slow cooker, and cook on high with the lid off for 1/2 hour. This cooks down the sherry and evaporates the alcohol.

Step 4. Add the broths & soy sauce.

Step 5. Tie the thyme sprigs into a bundle with cooking twine. Add the thyme, bay leaves, and black pepper to the soup. Stir, cover and cook for 1-2 hours. Remove the bay leaf and thyme sprigs.  Taste it to see if it needs more salt.

view on Amazon: spool of cooking twine

• Or, try speedier finishing on the stove-top, if desired. Transfer the caramelized onions to a stove-top pan. Add the sherry and cook on medium-high heat for 10 minutes. Add the broths, soy sauce, and seasonings; cover and simmer for 30 minutes.

Step 6. Refrigerate soup overnight, or up to two days. I usually cook for two, so I divide some of the soup into smaller freezer containers to freeze and thaw for quick bowls of soup in the future.

Step 7. When it's time to reheat the soup, I reheat a small portion in the microwave. Or, heat it on the stove top for larger quantities. 

Step 8. Prepare the bread that will go on top of the soup. I like to use a large piece of hearty whole grain bread that will cover all or most of the surface of the top of the soup. That way I get cheesy bread with every bite. Alternatively, you can use 2 or more smaller baguette slices. 

If using a larger slice, invert your soup bowl on top of the bread slice, press down, and break or cut off the edges of the bread. I use 10-oz. ramekins for soup bowls--they are inexpensive and oven safe. You can use any oven proof bowl.

view oven safe soup bowls on Amazon:
10-oz ramekins,  white bowls with handles,  brown ceramic soup crocks

Step 9. Place bread slices on a baking sheet, and toast in a 400 degree oven until the bread is dry and crisp, approx 10-15 minutes.

Step 10. Ladle heated soup into bowls, top with the toasted bread, sprinkle on grated Parmesan, and top with shredded Gruyere. You may substitute Swiss cheese for the Gruyere for a less expensive option. If you like your melted cheese stringy, mix half shredded mozzarella with the shredded Gruyere or Swiss.

Step 11. Put the bowls 6" below a pre-heated broiler. Keep a close watch and broil them just until the cheese completely melts, 3-4 minutes.

• Don't have oven proof bowls? No problem. Melt the cheese on top of the toasted bread and transfer the cheese toast to the top of hot bowls of soup.

And serve!

Timing it right to be ready when you want it. The long hours in the slow cooker and extra time in the fridge mean some planning ahead is necessary. Here are two possible plans.

• Start in the morning. Put the onions in the slower cooker to start caramelizing 1st thing in the morning (you can slice them the night before, if you want to). When they're nicely caramelized by evening, finish preparing the soup in either the slow cooker or on the stove top (if you want to speed things up). Put the soup in the fridge, and the next evening the soup is ready to heat, ladle into bowls, top with toasted bread and cheese. You can toast the bread the day before, or right before ladling the soup.
• Start in the evening. Put the onions in the slow cooker in the evening so they are caramelized when you get up in the morning. (You need to be okay with the house smelling oniony during the night and when you wake up.) Finish preparing the soup in either the slow cooker or on the stove top. Refrigerate until that evening or the next day, and proceed with preparing individual bowls of soup.

It will be a warm, comforting treat for your taste buds when you slurp a spoonful of this combination of richly flavored onion soup with the bread and melted cheese. Break off pieces of the cheese toast as you go, so you get that combo in every bite.

How inviting is that spoonful? Oh my.

Make it a Yummy day!
Monica 

Slow Cooker French Onion Soup

By Monica              Servings: 6-8 servings

Ingredients

• FOR CARAMELIZED ONIONS:
• 6 large yellow onions
• 2 tablespoons olive oil
• FOR SOUP:
• 1/2 cup dry sherry
• 4 cups chicken broth (low-sodium recommended)
• 2 cups beef broth
• 1/3 cup reduced sodium soy sauce
• 6 sprigs fresh thyme, tied in bundle with twine
• 1 bay leaf
• 1/2 teaspoon ground black pepper
• salt to taste
• FOR CHEESY TOASTED BREAD TOPPING:
• 6 large hearty bread slices (1/2" thick) cut to fit inside top of soup bowl; or 12 (or more) small baguette slices
• 6 tablespoons grated Parmesan cheese
• 2-1/2 cups (8 oz) shredded Gruyere cheese (may substitute Swiss; or, for stringier melted cheese use half shredded mozzarella)

Directions

Step 1, Caramelize the Onions:
Cut the peeled onions in halves and then quarters from pole to pole. Cut each quarter, pole to pole, in 1/4 inch slices. Coat inside of slow cooker with cooking spray. Add sliced onions and olive oil to slow cooker; toss with tongs or 2 forks to separate slices and distribute olive oil. Cover and cook on high for approx. 12-14 hours, until browned to caramel color. Keep an eye on them during the last few hours of cooking time; if they begin to burn around the edges, stir, re-cover, and continue cooking until caramelized throughout.

Step 2, Make the Soup:
Add the sherry to the caramelized onions in the slow cooker, and cook on high with the lid off for 1/2 hour to evaporate the alcohol. Add chicken and beef broths & soy sauce. Tie thyme sprigs into a bundle with cooking twine. Add thyme, bay leaves, and black pepper to the soup. Stir, cover and cook on high for 1-1/2 hours. Remove bay leaf and thyme sprigs. Taste and add salt, if needed. (For speedier finishing on the stove-top, transfer caramelized onions to a large stove-top pan. Add the sherry and cook on medium-high heat for 10 minutes. Add the broths, soy sauce, and seasonings; cover and simmer for 30 minutes.)

Step 3, Refrigerate:
Put soup in fridge overnight or up to 2 days.

Step 4, Prepare the Bread:
Place bread slices on a baking sheet, and toast in a 400 degree oven until the bread is dry and crisp, approx. 10-15 minutes.

Step 5, Assemble and Broil Individual Bowls:
Reheat desired amount of soup in microwave or on stove top. Ladle heated soup into individual oven-safe bowls, top with the toasted bread, sprinkle on grated Parmesan, and then shredded Gruyere. Adjust oven rack to 6" below broiler. Place bowls on baking sheet and broil just until cheese completely melts, 3-4 minutes. (If you don't have oven proof bowls, melt the cheese on top of the toasted bread and transfer the cheese toast to the top of filled bowls of hot soup.)

The soup (minus the bread and cheese) freezes well.

Nutritional Info (for one 10-oz serving topped with bread and cheese): 289 calories, 16g fat, 22.7g carbs, 4.1g fiber, 5.6g sugar, 17.3g protein; Weight Watchers PointPlus: 8