Heat a large skillet with 1 Tbsp. of olive oil over medium heat. Brown the chicken, seasoned with salt and pepper, about 3-5 minutes per side. Then, add 1/3 cup of water to the pan, cover and continue to cook for 8-15 minutes, until internal temperature reaches 165 degrees.
Preheat the oven to 400 degrees. Slice zucchini in half length-wise. Then, use a spoon to scoop out the seeds and part of the flesh. Brush with olive oil and season with salt and pepper. Bake for 8 minutes.
Remove from the oven. Next, top each boat with marinara sauce, grilled chicken, mozzarella, Parmesan cheese, and oregano. Return to the oven for 8-10 minutes. Finally, garnish with fresh basil. Serve with a simple Italian salad.