1. Prepare the Chicken and Season: Start by patting the chicken cubes dry with a paper towel. This helps them brown nicely. In a medium bowl, toss the chicken with chili powder, ground cumin, garlic powder, salt, and black pepper until evenly coated. Make sure each piece gets a good dusting of seasoning.

2. Saute the Chicken: Heat the olive oil in a large oven-safe skillet (cast iron or stainless steel works best) over medium-high heat. Once the oil is shimmering, add the seasoned chicken in a single layer. Cook for 5-7 minutes, stirring occasionally, until the chicken is browned on all sides and mostly cooked through. It doesn’t need to be fully cooked at this stage, as it will finish cooking with the zucchini.

3. Add the Zucchini: Reduce the heat to medium. Add the zucchini rounds to the skillet with the chicken. Cook for another 5-7 minutes, stirring occasionally, until the zucchini starts to soften slightly but still retains a bit of crispness. You want it tender-crisp, not mushy.

4. Introduce the Sauce and Toppings: Pour the pizza sauce evenly over the chicken and zucchini mixture in the skillet. Gently stir to combine, ensuring everything is coated.

5. Melt the Cheese: Sprinkle the shredded mozzarella and cheddar cheese evenly over the top of the skillet mixture. If using, scatter the sliced black olives over the cheese.

6. Finish in the Oven (or on Stovetop): If your skillet is oven-safe, transfer it to a preheated oven at 375 F (190 C) and bake for 5-8 minutes, or until the cheese is bubbly and lightly browned. Alternatively, if your skillet is not oven-safe, cover the skillet with a lid and continue cooking on the stovetop over low heat for 5-7 minutes, or until the cheese is fully melted and bubbly.

7. Garnish and Serve: Carefully remove the skillet from the oven or stovetop. Let it rest for a minute or two. Garnish with fresh chopped cilantro or parsley, if desired, before serving hot directly from the skillet.