• Step 1: Preheat your oven to 375°F. Bring a large pot of salted water to a boil and cook the elbow macaroni according to package instructions. Drain and set aside.
• Step 2: In a large skillet, melt the butter over medium heat. Add the diced chicken and cook until no longer pink, about 6-8 minutes. Remove the chicken from the skillet and set aside.
• Step 3: In the same skillet, whisk the flour into the butter until a roux forms. Gradually pour in the milk, whisking constantly to prevent lumps. Bring the mixture to a simmer and cook until thickened, about 5 minutes.
• Step 4: Remove the skillet from heat and stir in the shredded cheddar cheese, salt, pepper, and garlic powder until the cheese is melted and the sauce is smooth.
• Step 5: Add the cooked macaroni and chicken to the cheese sauce, stirring to combine. Transfer the mixture to a baking dish and bake for 20-25 minutes, or until the top is golden brown and bubbly.