Tender beef meatballs simmered in a rich caramelized onion sauce and topped with melted Gruyère — a cozy twist on classic French onion soup.
For the meatballs:
1 lb ground beef
1/3 cup panko breadcrumbs
1 egg
1 tbsp Worcestershire sauce
2 garlic cloves, minced
1 tsp salt
1/2 tsp black pepper
1 tsp fresh thyme (or 1/2 tsp dried)
For the sauce:
3 large yellow onions, thinly sliced
2 tbsp butter
1 tbsp olive oil
2 cups beef broth
1 tbsp flour
1 tsp Worcestershire sauce
2–3 thyme sprigs
1/2 cup shredded Gruyère or Swiss cheese
Caramelize onions in butter and olive oil over medium-low heat until golden and jammy (30–40 minutes).
Mix all meatball ingredients and form into 1.5-inch balls. Chill if needed.
Brown meatballs in a skillet and set aside.
Add flour to onions, stir, then slowly add beef broth. Simmer until slightly thickened.
Return meatballs to the skillet and simmer 10–15 minutes until fully cooked.
Top with cheese, cover, and let melt or broil briefly.
Serve hot with sauce over mashed potatoes, noodles, or bread.