French onion mac and cheese

Ingredients 6 Tbsp unsalted butter 2 Tbsp olive oil 3 large yellow onions, sliced 1 lb cavatappi pasta ¼ c all-purpose flour 2½ c 2% milk 2 c Fontina cheese, shredded 2 c Asiago cheese, shredded 8 oz mascarpone cheese 1 tsp salt 2 c croutons 3 c Gruyere cheese, shredded Directions 1. Heat 2 tablespoons butter and olive oil over medium low heat in a large non-stick skillet. Add onions,…