Go Back
It's easy to make this delicious French Onion Soup with a few simple steps and in a slow cooker. Add a thick piece of bread and cheese for a tasty topping!
Print Recipe Pin Recipe Save this Recipe

Please leave a rating!

5 from 2 votes

French Onion Soup

Start this the night before you want to serve it because the onions caramelize in the slow cooker overnight!
Servings: 6 servings
Author: Jurga

Ingredients

  • 4 large yellow onions, thinly sliced
  • 4 Tablespoons butter, melted
  • 2 Tablespoons olive oil
  • 1 teaspoon salt
  • ¼ teaspoon dried thyme
  • 2 cloves garlic, minced
  • ¼ cup dry red wine or sherry
  • 1 Tablespoon balsamic vinegar
  • 4 cups low sodium beef stock, preferably homemade
  • 4 cups low sodium chicken stock, preferably homemade
  • Salt and pepper to taste
  • 4-6 slices French bread cut into 1 inch thick slices, toasted
  • 8-12 Tablespoons freshly grated Parmesan cheese
  • 8-12 Tablespoons freshly grated Gruyère (or Swiss) cheese

Instructions

  • Toss sliced onions with melted butter, oil and salt and place them in a lightly greased slow cooker.
  • Cook on low and let the the onions caramelize over night, 10-12 hours.
  • In the morning, throw in the thyme, minced garlic, red wine, balsamic vinegar, beef stock, chicken stock and S&P to taste.
  • Cook on low for 8-10 hours.
  • Preheat the oven broiler.
  • Arrange the bread slices in a single layer on a baking sheet and broil 2 minutes, turning once until lightly toasted on both sides.
  • Remove from the heat; do not turn off the broiler.
  • Arrange oven-proof soup bowls on a rimmed baking sheet.
  • Fill each bowl ⅔ full of soup.
  • Place the toasted bread slices on top of the soup.
  • Sprinkle the bread slices with 2 Tablespoons each of the Parmesan and Gruyère cheeses.
  • Broil 5 minutes or until bread and cheese are golden brown.
  • Serve immediately!

Notes

Gr8 Tips:
For a thick and beautifully melted crusted topping, use oven-safe crocks and thicker pieces of bread. Top each bowl with sliced (not shredded) Gruyère or Swiss cheese overlapping the slices onto the sides. Broil until the cheese softens and cascades over the side of the crock, about 5 minutes.It's easy to make this delicious French Onion Soup with a few simple steps and in a slow cooker. Add a thick piece of bread and cheese for a tasty topping!
To get the very thinnest slices of onions, use a mandolin.French Onion Soup thinly cut onions.
Tried this recipe?Mention @Great8Friends or tag #gr8food!