I slightly adapted it from Bon Apetit/Epicurious. And I used Wondra flour but you could use regular flour.
I love that you can skip a step by not precooking the pasta. Instead, mix the dried pasta with a thinner-than-usual béchamel sauce, and it will bake perfectly in just 30 minutes.
Ingredients:1/2 cup (1 stick) unsalted butter, divided
1/4 cup all-purpose Wondra flour
3 cups whole milk
3 cups chicken stock
1/2 tablespoon kosher salt
1/4 teaspoon freshly ground black pepper
1 pound elbow macaroni
2 cups shredded cheddar, divided
2 garlic cloves, chopped
2-3 Tablespoons grated Parmesan cheese
1 cup panko (Japanese breadcrumbs)
2 tablespoons chopped flat-leaf parsley (I used 1 teaspoon dried)
Preparation:Preheat oven to 400°F. Melt 1/4 cup butter in a large saucepan over medium-high heat. Add Wondra flour; cook, whisking constantly, for 1 minute. Whisk in milk and 3 cups chicken broth. Bring to a boil, reduce heat to a simmer, and cook, whisking often, until a very thin, glossy sauce forms, about 10 minutes. Stir in salt and pepper. Remove sauce from heat.
Toss pasta and 1 1/2 cups cheese in a 13x9x2" or other shallow 3-quart baking dish. Pour sauce over (pasta should be submerged; do not stir) and cover with foil. Bake until pasta is almost tender, about 20 minutes.
Meanwhile, melt remaining 1/4 cup butter in a large skillet over medium heat. Add garlic, Parmesan, panko, and parsley and toss to combine.
Remove foil from dish. Sprinkle with remaining 1/2 cup cheese, then panko mixture. Bake until pasta is tender, edges are bubbling, and top is golden brown, about 10 minutes longer. Let sit 10 minutes before serving