Heat olive oil in a large skillet over medium-high heat. Season chicken with cumin, chili powder, and salt.
Cook chicken in the skillet for 6-7 minutes on each side or until fully cooked. Remove from heat and let rest.
Chop chicken into bite-sized pieces and set aside.
In a bowl, combine pineapple, red onion, cilantro, and lime juice. Mix well to prepare the salsa.
Assemble tacos with chopped chicken, pineapple salsa, and avocado slices. Serve immediately.
Notes
This recipe can be easily made gluten-free by using corn tortillas instead of flour tortillas. Adjust spice levels by adding more or less chili powder to taste.