01 -
Preheat your oven to 325°F and grease a 3-quart (9x13") baking dish. Set it aside while you boil the pasta.
02 -
Bring a large pot of salted water to a boil. Add the elbow pasta and cook 1 minute less than package directions for al dente. Drain and drizzle lightly with olive oil to prevent sticking.
03 -
Shred both the cheddar and Gruyere cheeses. Mix them together and divide into three portions: about 3 cups for the sauce, 1½ cups for the middle layer, and 1½ cups for the topping.
04 -
In a large saucepan over medium heat, melt the butter. Sprinkle in the flour and whisk for about 1 minute. Gradually whisk in the half and half and milk until the mixture is smooth. Continue whisking often until it thickens to a semi-condensed soup consistency.
05 -
Remove the sauce from heat. Stir in the salt, pepper, paprika, and 3 cups of the cheese mix. Stir until the cheese melts completely and the sauce is smooth.
06 -
In a large bowl, combine the cooked pasta with the cheese sauce. Pour half into the prepared baking dish, sprinkle with 1½ cups of cheese, then add the remaining pasta. Top with the final 1½ cups of cheese.
07 -
Bake uncovered at 325°F for about 15 minutes, or until the cheese is melted and bubbly with a lightly golden top.