In a large skillet, heat a tablespoon of vegetable oil over medium heat. Add the chopped onion and garlic, and sauté until softened.
Add the ground beef or chicken to the skillet and cook until browned. Stir in the bell pepper, black beans (if using), grated carrots, and chopped tomatoes. Cook for an additional 5 minutes.
Stir in the tomato paste, ground cumin, paprika, oregano, salt, and pepper. Mix well and let it simmer for another 10 minutes. Remove from heat and set aside.
In a separate skillet, heat about 1/2 inch of vegetable oil over medium heat.
Fry the corn tortillas one at a time until they are golden and slightly crispy, about 1-2 minutes per side. Drain on paper towels to remove excess oil.
Place a spoonful of the filling onto each fried tortilla and fold them in half to form a half-moon shape.
Arrange the filled tortillas on a serving platter.
Top each enchilada with shredded lettuce, grated cheese, sliced radishes, and chopped cilantro.
Drizzle with sour cream and hot sauce if desired.
Enjoy your meal!