Balanced Slow-Cooker French Onion Soup (Overnight)

A more balanced take on slow-cooker French onion soup: a little less butter/cheese, more fiber/protein via optional mushrooms and beans, and lower-sodium options—without losing the deep, caramelized flavor.

Great

% Daily Values based on a 2,000 calorie diet

Step 1

Add the sliced onions to a 5–7 quart slow cooker. Drizzle with melted butter and olive oil. Sprinkle with salt and pepper, then toss to coat.

Step 2

Add thyme (and garlic, if using). If using mushrooms, add them now. Cover and cook on LOW for 10–12 hours (overnight).

Step 3

In the morning, uncover and stir. If there is excess liquid, cook uncovered on HIGH for 15–30 minutes to help concentrate and deepen color.

Step 4

Stir in tomato paste (if using) and cook on HIGH for 5 minutes to remove the raw taste.

Step 5

Add balsamic vinegar (and brandy, if using). Stir, then cook on HIGH for 10 minutes to let the alcohol cook off and flavors meld.

Step 6

Pour in the broth. Cover and cook on HIGH for 30–60 minutes (or LOW for 1–2 hours). Taste and adjust salt/pepper as needed.

Step 7

If using beans, stir them in during the last 10–15 minutes just to warm through (they’ll slightly thicken the soup). Remove thyme sprigs before serving.

Step 8

To serve: ladle soup into oven-safe bowls. Top each with 1 toasted baguette slice and about 1/4 cup Gruyère (or 1 tbsp nutritional yeast). Broil 1–3 minutes until bubbly (or cover with a lid for a melt without broiling).

Step 9

Garnish with parsley or thyme and serve hot.