Heat olive oil in a large cast-iron skillet or heavy-bottomed pan over medium-high heat. Season chicken pieces with salt, pepper, cumin, and chili powder, then add to the hot skillet. Cook for 5-6 minutes, stirring occasionally, until the chicken develops golden-brown edges and is nearly cooked through. Remove chicken to a plate and set aside.

In the same skillet, add diced onion and bell pepper to the browned bits. Cook for 3-4 minutes until the vegetables start to soften and smell fragrant. Add minced garlic and cook for another 30 seconds until aromatic.

Pour in the enchilada sauce, drained diced tomatoes, and green chiles, stirring to combine everything evenly. Add paprika and season with salt and pepper to taste. Let this simmer for 2-3 minutes to allow the flavors to meld together.

Return the browned chicken to the skillet, nestling the pieces into the sauce. Reduce heat to medium-low and let everything simmer together for 8-10 minutes, stirring occasionally, until chicken is tender and sauce coats everything.

Sprinkle the shredded cheese evenly over the entire surface. Cover with a lid or foil and let it rest off the heat for 2-3 minutes until the cheese melts completely. Garnish with fresh cilantro and sliced green onions.