Slow Cooker French Onion Meatballs

You’ll want a straw to slurp up all that sauce (but a baguette works, too)

Prep: 20 mins

Cook: 5 hrs 10 mins

Total: 5 hrs 30 mins

Servings: 4 to 6 servings

Yield: 24 meatballs

French onion meatballs combine all the flavors and ingredients found in a classic French onion soup, packing them into a hearty main dish or appetizer sure to impress friends and family.

Ingredients in French Onion Meatballs

I doubled down on the onion flavor by adding dry onion soup mix to the meatballs, and the condensed French onion soup ensures a rich, flavorful broth, even after a few hours in the slow cooker. The onion-forward broth, melty cheese, and toasted baguette slices mimic the iconic soup.

Use a Slow Cooker for a Nearly Effortless Dish

The slow cooker makes this fabulous dish nearly effortless. There's no need to caramelize the onions on the stovetop, which can take up to 1 hour of cooking and stirring. In the slow cooker, the seasoned onions release their juices and soften beautifully, freeing you to attend to other tasks.

How to Serve French Onion Meatballs as a Party Appetizer

French onion meatballs are easy and versatile. Serve them as a main dish or party appetizer. The meatballs make an excellent dish for a tail-gating event or gameday gathering. For serving, you can keep the meatballs warm in the slow cooker for up to 4 hours.

What To Serve With French Onion Meatballs

As a main dish, spoon the meatballs and sauce over a mound of mashed potatoes, rice, or polenta, or serve them with toasted baguette slices or garlic bread. Add extra beef broth for a soupier dish.

For an attractive presentation, transfer the cooked meatball and onion mixture to an iron skillet or baking dish (not glass), top it with the cheese, and place it under the broiler for a minute or two until the cheese melts.

For fancier individual servings, portion the slow-cooked meatballs and sauce into ramekins, top with a baguette slice, and sprinkle a generous amount of shredded cheese over each serving. Broil until the cheese is melted and lightly browned, about 1 minute.

Tips for Making French Onion Meatballs

Slicing the onions—A mandoline or food processor with a slicing disk are excellent ways to slice the onions quickly and ensure uniform slices.
Avoid oversalting—If the broth is salty, you might not have to add more. Wait until the sauce is nearly done, then taste it and add salt if needed.
Lean is best—Choose lean ground beef with a ratio of lean to fat of 85/15 or 90/10.
Which size slow cooker to use—A 6 to 7-quart slow cooker is ideal. If your slow cooker is smaller, stir the onions every 30 to 45 minutes to ensure even cooking.

Make Ahead

You can save some time by making the meatballs ahead of time. Refrigerate unbaked meatballs overnight or freeze them for up to 1 month. Alternatively, refrigerate baked meatballs for up to 2 days or freeze them for up to 2 months.
You can slice the onions and refrigerate them in an airtight container for up to 2 days.

“Slow cooker French onion meatballs are traditional comfort food made even better with the addition of grated gruyere cheese and toasted baguette to serve. A perfect meal on a cold rainy night.” —Joan Velush

A Note From Our Recipe Tester

Ingredients

For the Onions

3 large onions, thinly sliced, about 6 cups
2 large cloves garlic, minced
1 large bay leaf
1 tablespoon unsalted butter
1 tablespoon balsamic vinegar
2 teaspoons Worcestershire sauce
1 teaspoon fine salt
Freshly ground black pepper, to taste

For the Meatballs

1 1/2 pounds lean ground beef (85/15 or 90/10)
1/2 cup panko breadcrumbs
1 packet (1 ounce) dry onion soup mix
1 large egg
1/2 teaspoon herbes de Provence or dried thyme

For the Sauce and Finishing

1 (10.5-ounce) can condensed French onion soup
1 cup unsalted beef broth or water
1/2 teaspoon herbes de Provence or dried thyme
1 1/2 to 2 cups (6 to 8 ounces) shredded Gruyère or Swiss cheese
Fresh thyme leaves or fresh chopped parsley, for garnish, optional
1 baguette, sliced and toasted

Steps to Make It

Gather the ingredients.
Combine 3 large onions, thinly sliced (about 6 cups), 2 large cloves garlic, minced, 1 large bay leaf, 1 tablespoon unsalted butter, 1 tablespoon balsamic vinegar, 2 teaspoons Worcestershire sauce, 1 teaspoon fine salt, and freshly ground black pepper to taste in a large slow cooker and give everything a stir to combine. Cover and cook on high for 3 hours, stirring again after 1 hour.
About 25 minutes before the 3 hours is up, prepare the meatballs. Position a rack in the center of the oven and heat to 425 F. Line a large rimmed baking sheet with foil.

In a large bowl, combine 1 1/2 pounds lean ground beef (85/15 or 90/10) with 1/2 cup panko breadcrumbs, 1 packet (1 ounce) dry onion soup mix, 1 large egg, and 1/2 teaspoon herbes de Provence or dried thyme.
Mix until the ingredients are combined (but do not overmix) and using 2 tablespoons or a 2-tablespoon portion scoop, shape the mixture into 24 to 28 1-ounce meatballs and place on the prepared baking sheet.
Bake the meatballs in the oven for 10 minutes.
Add the meatballs, 1 can (10.5 ounces) condensed French onion soup, 1 cup unsalted beef broth or water, and 1/2 teaspoon herbes de Provence or dried thyme to the slow cooker.
Cover and cook on high for 2 hours. Taste and adjust the seasonings. Turn the slow cooker to warm until it’s time to serve the meatballs.
Just before serving, sprinkle the meatballs evenly with 1 1/2 to 2 cups (6 to 8 ounces) shredded Gruyère cheese. Cover and let the
meatballs stand until the cheese is melted, 5 to 10 minutes.
Garnish the meatballs with fresh thyme leaves or chopped parsley if desired, and serve them with 1 baguette, sliced and toasted.

How To Store

Refrigerate leftover meatballs with their juices and cheese in a shallow airtight container within 2 hours, and enjoy them within 3 to 4 days.
To freeze — Transfer the cooled meatballs to a resealable freezer bag or airtight freezer container. Label the bag or container with the name and date and freeze for up to 2 months. Defrost the meatballs in the freezer overnight.
To reheat — Transfer the French onion meatballs to a saucepan with a splash of broth or water. Cover the pan and heat over medium-low heat, stirring frequently, until they reach 165 F on a food thermometer inserted into the center of a meatball.

Feeling Adventurous? Try This:

Use another ground meat—Instead of ground beef, use ground turkey, chicken, or a plant-based ground beef substitute in the recipe.
Vary the seasonings—Herbes de Provence is a French blend of herbs. You can replace the herbes de Provence with Italian seasoning or use a combination of equal amounts of dried thyme and rosemary and a pinch of marjoram or oregano.
Grate up a different cheese—Classic French onion soup typically contains Gruyere, a slightly sweet, nutty cheese. Fontina is more mild, but its nutty flavor and melting qualities make it an excellent substitute. Mozzarella is another good choice, though it tends to be a bit greasier.

Nutrition Facts
Servings: 4 to 6
Amount per serving
Calories	489
% Daily Value*
Total Fat 26g	34%
Saturated Fat 13g	66%
Cholesterol 155mg	52%
Sodium 1656mg	72%
Total Carbohydrate 21g	8%
Dietary Fiber 2g	8%
Total Sugars 6g
Protein 40g
Vitamin C 4mg	21%
Calcium 459mg	35%
Iron 4mg	21%
Potassium 835mg	18%
*The % Daily Value (DV) tells you how much a nutrient in a food serving contributes to a daily diet. 2,000 calories a day is used for general nutrition advice.