Preheat the oven to 400F.

Combine chicken breast chunks along with 1 tbsp olive oil and all spices (cumin through oregano) in a large ziploc bag. Shake to combine then let marinate in the fridge for at least 30 minutes.

When ready to cook, heat the remaining 1 tablespoon of olive oil in a large cast-iron skillet (or another oven safe pan) over medium. Once the oil is hot, add the contents of the chicken ziploc bag then spread the chicken pieces out evenly in a single layer and cook for about 10-13 minutes, tossing occasionally, or until nicely browned on all sides and almost cooked through. Once done, transfer onto a plate and set aside.

In the same skillet still heating over medium, add the onion, tomato, and jalapeño and sauté until soft, about 5 minutes, stirring occasionally.

Return the cooked chicken chunks to the skillet then stir to mix them up with sautéed onions, tomato, and jalapeno. Top the skillet with shredded cheddar (if you don't have a cast-iron/oven safe skillet, transfer the chicken mixture to a 9x13-inch casserole pan then top it with the cheese).