In a large skillet, heat the olive oil over medium heat. Add the diced onion and sauté for about 3-4 minutes until softened. Add the minced garlic and cook for an additional 1 minute until fragrant.

Add the ground chicken to the skillet, breaking it apart with a spatula. Cook until browned and fully cooked, about 5-7 minutes.

Stir in the chili powder, cumin, paprika, salt, black pepper, and cayenne pepper (if using). Mix well to coat the chicken evenly with the spices.

Pour in the chicken broth and let the mixture simmer for about 3-4 minutes, allowing the flavors to meld and the liquid to reduce slightly.

While the chicken is cooking, warm the tortillas in a dry skillet or microwave until pliable.

To assemble the tacos, place a generous scoop of the ground chicken mixture onto each tortilla. Top with shredded lettuce, diced tomatoes, cheese, sour cream, and cilantro if desired.

Serve immediately with lime wedges on the side for squeezing over the tacos.