• Preheat oven to 350°F.

Caramelized Onions

• Heat a skillet over medium-high heat and when hot, add the oil, butter, and onions.
• Turn the heat to low and cover with a lid and cook for 25-30 minutes until the onions are softened.
• Turn the heat to medium, uncover, and cook until the onions are golden brown, stirring occasionally
• Cover and remove the pan from the heat and set aside.

Mac and Cheese

• In a saucepan over medium heat, melt the butter.
• Add the flour and whisk constantly for 1-2 minutes (or until the mixture turns light brown).
• Remove from heat and gradually pour in the warm milk and beef stock, whisking constantly.
• Return the pan to the heat, whisk another 3-5 minutes or until thickened.
• Add the salt, garlic powder, ground mustard, and cayenne pepper and stir to combine.
• Add the cheeses and onion mixture, stir until all of the cheese is melted.
• Pour the sauce over the top of the cooked elbow macaroni. Stir to combine.
• Add the shredded rotisserie chicken and stir until completely mixed together.

Topping

• Top with ¼ cup shredded Gruyere cheese
• Bake, uncovered, for 12-15 minutes, or until golden brown.
• Season with salt and pepper, and top with chopped thyme.