1️⃣ Preheat the Oven:
Preheat your oven to 350°F (175°C). Lightly spray a 9×13-inch baking dish with cooking spray. 🔥

2️⃣ Prepare the Pasta:
Cook the spaghetti according to the package directions until al dente. Drain and set aside. 🍝

3️⃣ Mix Ingredients:
In a large bowl, combine the cooked chicken, cream of chicken soup, sour cream, drained spinach, 1 cup of Monterey Jack cheese, minced garlic, and half a can of French Fried Onions. 🥄

4️⃣ Combine Pasta and Mixture:
Stir the cooked spaghetti into the chicken mixture until fully combined. Pour the mixture into the prepared baking dish. 🍲

5️⃣ Add Toppings:
Sprinkle the remaining Monterey Jack cheese over the pasta mixture, then top with the rest of the French Fried Onions. 🧅🧀

6️⃣ Bake:
Bake uncovered for 40 to 50 minutes, until the casserole is hot, bubbly, and the onions are golden brown. 🍽️⏳