In a large Dutch oven or deep skillet, melt the butter over medium heat. Add the diced onion and cook until soft and translucent, about 4 minutes. Stir in the minced garlic and cook for another 30 seconds until fragrant.

Pour in the cream of chicken soup, milk, and chicken broth. Whisk until smooth and combined. Bring the mixture to a gentle simmer, stirring occasionally. The sauce should thicken slightly as it heats. Add the dried thyme, salt, and pepper. Taste and adjust seasoning.

Stir in the uncooked elbow macaroni, frozen peas and carrots, and the cooked chicken. Make sure everything is submerged in the liquid. If the pasta isn’t fully covered, add a little extra broth or water. Cover the pot and let it simmer over medium low heat for about 12 to 15 minutes, stirring occasionally to prevent sticking.

After 12 minutes, test a piece of pasta. It should be al dente, with a slight bite. The sauce should be creamy and clinging to the noodles. If it seems too thick, add a splash of milk or broth to loosen it. If it’s too thin, let it simmer uncovered for a minute or two to reduce.

For that pot pie feel, sprinkle shredded cheddar cheese and breadcrumbs over the top of the pasta. Place the pot under the broiler for 2 to 3 minutes until golden and bubbly. Watch carefully so it doesn’t burn.

Let the pasta sit for 5 minutes off the heat. This allows the sauce to thicken further and the flavors to meld. Spoon into bowls and garnish with a pinch of fresh thyme or parsley if you have it. Serve warm.