Slice the chicken breast into thin, even strips and place them in a small mixing bowl.
Toss the chicken with the chili powder, smoked paprika, ground cumin, sea salt, and black pepper until thoroughly coated.
Heat the olive oil in a large cast-iron skillet over medium-high heat until it begins to shimmer.
Add the seasoned chicken strips to the skillet in a single layer and sear for 5-6 minutes, turning occasionally, until golden brown and cooked through.
Transfer the cooked chicken to a plate and set aside.
In the same skillet, add the sliced red bell pepper, green bell pepper, and red onion, sautéing for 4-5 minutes until tender-crisp with slight charred edges.
Return the chicken to the skillet, drizzle with fresh lime juice, and toss everything together for 1 minute to combine the flavors.
Remove from heat, garnish with freshly chopped cilantro, and serve immediately.