1. 1. Prepare the Chicken: If using raw chicken breasts or thighs, cut them into 1-inch cubes. If using pre-cooked chicken, shred or cube it and set aside.

2. 2. Saute Aromatics: Heat olive oil in a large skillet or Dutch oven over medium heat. Add the chopped onion and cook until softened, about 5-7 minutes. Stir in the minced garlic and cook for another minute until fragrant. Do not let the garlic burn.

3. 3. Combine Creamy Sauce: In a large mixing bowl, whisk together the cream of mushroom soup, cream of chicken soup, milk, Italian seasoning, black pepper, and salt until smooth.

4. 4. Mix Everything Together: Add the cubed raw chicken (or pre-cooked chicken) to the skillet with the sauteed onions and garlic. Pour the creamy soup mixture over the chicken and stir gently to ensure all the chicken is coated.

5. 5. Prepare for Baking: Transfer the chicken mixture to a 9×13 inch baking dish. At this point, you can either cover and refrigerate for later (see make-ahead instructions) or proceed to bake.

6. 6. Bake Until Done: Preheat your oven to 375 F (190 C). Bake the uncovered dish for 25-30 minutes, or until the chicken is cooked through (if using raw chicken) and the sauce is bubbly and slightly thickened. If using pre-cooked chicken, bake until heated through, about 20-25 minutes. The internal temperature of the chicken should reach 165 F (74 C).

7. 7. Serve and Garnish: Remove from the oven and let it rest for a few minutes. Garnish with fresh chopped parsley, if desired, and serve warm.