Wash the mini peppers, slice them in half lengthwise, and remove the seeds. Set aside.

In a skillet over medium heat, heat the oil or butter. Add the diced onion and cook until soft, about 3–4 minutes.

Add the ground beef and cook until browned, breaking it up with a spatula as it cooks. Drain any excess grease if needed.

Stir in the taco seasoning and cook for 1–2 minutes until well combined and fragrant.

Remove from heat and stir in ¾ cup of the shredded cheddar cheese until melted, reserving the rest for topping.

Arrange the pepper halves on a baking sheet or in a casserole dish. Spoon the beef mixture into each pepper.

Sprinkle the tops with the remaining cheese.

Let the filled peppers cool completely if they’re still warm.

Place them in a single layer on a baking sheet and freeze until solid (about 1–2 hours).

Transfer the frozen peppers to a labeled freezer-safe container or zip-top bag. Freeze for up to 3 months.

Place frozen stuffed peppers in a greased baking dish.

Cover with foil and bake at 375°F for 30–35 minutes, then uncover and bake an additional 5–10 minutes, or until the cheese is melted and the peppers are heated through.

Preheat oven to 375°F.

Bake stuffed peppers for 20–25 minutes, or until cheese is melted and bubbly