Prep the peppers: Preheat the oven to 400°F (200°C). Halve the mini peppers lengthwise and remove seeds and membranes.
Place them cut-side up on a parchment-lined baking sheet.
Sauté aromatics: Heat a large skillet over medium heat. Add olive oil, then onion. Cook 3–4 minutes until softened.
Stir in garlic and cook 30 seconds until fragrant.
Brown the meat: Add ground beef or turkey. Break it up with a spoon and cook until no longer pink, about 5–7 minutes. Drain excess fat if needed.
Season and simmer: Stir in taco seasoning, salt, and pepper.
Add tomato sauce and black beans. Simmer 2–3 minutes, stirring, until the mixture thickens slightly and tastes bold and savory. Remove from heat and stir in half the cilantro.
Pre-bake the peppers (optional but helpful): For extra-tender peppers, bake the empty halves for 5 minutes.
This step is optional; skip it if you like a firmer crunch.
Stuff and top with cheese: Spoon the warm taco mixture into each pepper half, slightly heaping. Sprinkle generously with shredded cheese.
Bake: Return the pan to the oven and bake 8–10 minutes, until the cheese is melted and bubbly and peppers are crisp-tender.
Finish with fresh toppings: Garnish with remaining cilantro. Add salsa or pico, a small dollop of sour cream, green onions, avocado, and pickled jalapeños as desired.
Squeeze lime over the top for brightness.
Serve hot: Arrange on a platter and serve immediately. Keep extra toppings on the side so everyone can build their own.