Season the chicken breast evenly on both sides with chili powder, cumin, garlic powder, sea salt, and black pepper.
Heat the avocado oil in a large skillet over medium-high heat until shimmering.
Place the chicken in the skillet and sear for 6 to 7 minutes per side until the exterior is golden brown and the internal temperature reaches 165°F.
Remove the chicken from the pan and let it rest for 5 minutes before slicing into thin strips.
In the same skillet, add the sliced bell peppers and red onions, sautéing for 5 to 6 minutes until they are tender and develop charred edges.
Prepare the base of the bowl by adding the chopped romaine lettuce.
Layer the sautéed peppers, onions, and sliced chicken over the lettuce.
Top the bowl with fresh avocado slices, salsa, cilantro, and a bright squeeze of lime juice before serving.