Make the Meatballs: In a small dish, soak the breadcrumbs in milk for a few minutes. Add the other meatball ingredients and mix. Add in the ground beef last.

Gently combine everything with your hands — don’t overmix or the meatballs will get tough. Scoop about 2 tablespoons of mixture per meatball (a cookie scoop works great) and roll into balls. Chill for 15 minutes in the fridge to help them hold their shape.

Sear the Meatballs: Heat some avocado oil in a large, heavy-bottomed skillet (cast iron works great) over medium-high heat. Cook the meatballs in batches until almost cooked through, about 15 minutes total. Transfer to a plate and set aside.

Caramelize the Onions: In the same skillet, add the remaining 2 tablespoons avocado oil and the ghee or butter. Add sliced onions with a pinch of salt and pepper. Cook on medium heat, stirring often, for 30–35 minutes until deep golden brown and jammy.

👉 Shortcut tip: If you’re short on time, add 1 teaspoon of sugar or honey to speed up caramelization — just stir often to avoid burning.

Build the Sauce: Add garlic, herbes de Provence, and dried thyme to the onions and cook 30 seconds, until fragrant. Deglaze with sherry or wine, scraping up any browned bits. Sprinkle in the flour, stir to combine, then slowly pour in the beef stock while whisking to create a smooth sauce. Let it simmer 5 minutes to thicken slightly.

Broil & Melt: Turn off the heat, stir in the thyme, and nestle the seared meatballs back into the sauce. Top with the remaining Gruyère and mozzarella. Place under the broiler on High for 5–7 minutes, until bubbly, gooey, and golden on top.

Serve & Enjoy: Spoon 3–4 meatballs with plenty of sauce and cheese over egg noodles or mashed potatoes.

Prepare yourself for instant dinner hero status.