3Tbspunsalted butter, best quality you can find (high butterfat percentage)
2 1/2Tbspflour
1 1/2cupwhole milk
1/2cupheavy cream
2cupsGruyere, grated, freshly and in large pieces
Topping
2Tbspunsalted butter
1/4cupParmigiano Reggianofinely grated
3/4cuppanko breadcrumbs
fleur de sel to taste
freshly ground black pepperto taste
Instructions
Preheat oven to 350 degrees (180 Celsius).
Bring a pot of water to boil and cook the elbow pasta to al dente, but no more. Drain and set aside. Toss with 1 tsp of olive oil to prevent from sticking together. Set aside while you make the sauce.
Make the béchamel sauce: In a medium sauce pan over low heat, melt the butter. Once the butter has melted, gradually add the flour, whisking as you add until smooth. Then add the milk and cream. Whisk until smooth and slightly thickening. Lastly, add the Gruyere and and whisk until smooth and all is combined. Sauce should become thick. Add salt and pepper to taste.
Use a medium souffle pan or 8x8 casserole dish. Place the pasta in the pan/dish. Pour the cheese sauce over the pasta and mix until tossed and all elbow pasta has sauce.
In a dry skillet, add the panko and butter over med-low heat. Lightly toast the panko or stir with a wooden spoon (not to brown, but to add flavor from the butter). Toss consistently so as not to burn. Using a food processor, combine the panko breadcrumbs and Parmigiana Reggiano. Sprinkle on top of the pasta and sauce, evenly and don't be stingy.
Bake in the oven for 30 minutes. Top should be golden brown. Serve immediately and enjoy with a side of roasted vegetables and a glass of wine.