While macaroni cooks, melt butter in a large pan over medium heat.
Reduce heat to low, add 1/2 tsp salt, and 1/4 tsp pepper to pan. Use a whisk to stir until the mixture is bubbly.
Add milk and bring to a boil, stirring constantly. Boil for 1 minute, stirring constantly, then remove bechamel sauce from heat.
Place half the cooked macaroni (about 1 1/2 cups) on the bottom of a square 9x9 baking dish. Sprinkle with 1/8 tsp salt and 1/8 tsp garlic salt. Top with 1 1/2 cups shredded cheese. Repeat the layers one more time.
Pour white becamel sauce over the top of the final cheese layer.
Add cubed butter on top of sauce and cover with foil.
Bake for 30 minutes covered with foil. Remove foil and bake for an additional 15-20 minutes or until top is beginning to brown.
Stir the bechamel sauce constantly while you’re cooking it. You don’t want any part of it to burn or brown or it’ll change the flavor of the sauce.Cook the macaroni to al dente since they’ll get cooked a bit more in the oven and you don’t want them to end up totally mushy.Double the recipe by simply doubling the ingredients and baking it in a 9×13 casserole dish instead. This is a great meal for a crowd, a party, or a holiday feast!Up the salt in the recipe by 1/2 tsp if you like your macaroni and cheese a bit salty. We like to salt to taste since my husband and I have different salt preferences – if you like a bit more salty, go for 1 1/4 tsp salt instead.