Peel and finely chop the onion and garlic. Melt the butter in a sauté pan and gently sauté the onion and garlic over low heat.
Add the ground beef and cook together for about 10 minutes.
Drain and cut the peppers into thin strips. Mix them with the tomato pulp and cumin, then incorporate everything into the beef. Season with salt and pepper, then let simmer over low heat for 10 minutes.
Preheat the oven to grill mode.
Fill the mini tortillas with the beef mixture and sprinkle mozzarella over each one.
Place them on a baking tray and grill for 5 minutes.
Enjoy right out of the oven!