Preheat the oven to 350°F (175°C).
In a large skillet over medium heat, add the ground beef. Cook until browned, breaking it apart with a spoon. Drain excess fat if necessary.
Add the diced onions, bell peppers, and minced garlic to the skillet with the beef. Continue cooking for about 5 minutes until the vegetables are soft.
Stir in cumin, chili powder, paprika, salt, and pepper. Mix thoroughly and cook for another 2-3 minutes. Remove from heat.
Slice the zucchini lengthwise into thin strips (approximately ¼ inch thick) to create the 'tortillas.'
In a baking dish, lay down 4 strips of zucchini to form a base. Distribute half of the beef mixture across the center of the zucchini. Sprinkle with ½ cup of cheese.
Roll the zucchini around the filling to create enchiladas. Repeat with the remaining strips and beef mixture. Place all rolled enchiladas seam-side down in the baking dish.
Pour the salsa over the top of the enchiladas and sprinkle remaining cheese on top.
If desired, cover the baking dish with foil and bake for 20 minutes. For a bubbly top, remove the foil and bake for an additional 5-10 minutes until cheese is melted and golden.
Allow to cool for a few minutes, then serve warm. Top with sour cream if desired.