In a large skillet, heat the olive oil over medium heat. Add the chopped onion and sauté for about 3-4 minutes until softened.

Add the minced garlic and cook for an additional 1 minute until fragrant.

Increase the heat to medium-high and add the ground turkey. Cook until browned, breaking it apart with a spoon, about 5-7 minutes.

Stir in the chili powder, cumin, paprika, salt, black pepper, and cayenne pepper (if using). Mix well and cook for another 2-3 minutes.

Add the diced tomatoes and simmer for 5 minutes, allowing the flavors to meld.

While the turkey mixture is simmering, heat the corn tortillas in a separate skillet over medium heat for about 30 seconds on each side until warm and slightly crispy.

To assemble, place a generous spoonful of the turkey mixture onto each tortilla. Top with shredded lettuce, diced avocado, shredded cheese, and a dollop of sour cream.

Garnish with fresh cilantro before serving.