Preheat the oven to 180℃
In a small bowl, mix the minced beef, diced onion, diced garlic, rosemary, oregano, cumin, salt, black pepper, egg, almond flour, and dijon mustard.
Next, take 2 tablespoon of meat batter and form it into a meatball. Repeat until you are out of meat batter. In the end, you should have approximately 16 meatballs.
Then add 2 tablespoon of olive oil to a skillet at medium-low heat. Allow the oil to heat for about one minute.
Afterward, add the meatballs to the skillet and let them sear for 3 minutes. Then flip the meatballs to the other side and let them sear for another 3 minutes.
Once the meatballs are cooked, to your preferred degree of doneness, transfer them to a casserole.
Add the basic tomato sauce to the casserole, and top it with basil and cheese. Then cover the casserole with aluminum foil.
Cook the meatballs in the oven on the middle rack for 25 minutes.