Instructions

1. Thaw 2 Maine or 4 small lobster tails in the refrigerator if needed.
2. Arrange a rack in the upper third of the oven and heat the oven to 450°F. Meanwhile, coat a 9x13-inch baking dish with cooking spray.
3. Place 1 cup panko breadcrumbs in a medium bowl. Place 3 tablespoons of the unsalted butter in a small microwave-safe bowl and microwave until melted. Transfer 2 tablespoons of the butter to the bowl with the breadcrumbs and toss until well combined.
4. Prepare the lobster tails one at a time: Position the tail upside down. Using kitchen shears and starting at the thicker end, cut down each side of the tail where the feelers meet the shell. Remove and discard the feelers to expose the tail meat. Place the tail cut side up on a rimmed baking sheet.
5. Brush the remaining 1 tablespoon melted unsalted butter over the flesh of the tails. Sprinkle with 1/4 teaspoon Old Bay seasoning. Bake until mostly cooked through, 10 to 12 minutes. Remove from the oven and let cool until lukewarm, about 15 minutes. Meanwhile, prepare the aromatics, pasta, and cheeses.
6. Bring a large pot of salted water to a boil over medium-high heat. Decrease the oven temperature to 375°F. Pick the leaves from a few fresh parsley sprigs and finely chop until you have 3 tablespoons. Mince 1/2 medium shallot (about 1/4 cup) and 2 large garlic cloves, and place both in a small bowl.
7. Grate the following cheeses on the large holes of a box grater and place in the same bowl: 5 ounces Gruyère (about 2 cups) and 8 ounces white cheddar (about 2 cups).
8. Grate 2 ounces Parmesan cheese on the small holes of the box grater (about 1 cup). Transfer half to the bowl with the breadcrumbs and toss to combine. Transfer the remaining to the bowl with the other cheeses and toss to combine.
9. Add 1 pound dry pasta to the boiling water and cook according to package instructions until just al dente, 8 to 11 minutes. Drain the pasta and dry the pot.
10. While wearing kitchen gloves if desired, remove the meat from the lobster tails and place on a clean cutting board; discard the shells. Coarsely chop the meat into 1/2 inch pieces (about 2 cups).
11. Add 2 tablespoons of the unsalted butter to the now-empty pot and melt over medium heat. Add the shallots and garlic and a pinch of kosher salt, and cook until tender and just turning golden on the edges, about 3 minutes.
12. Add 2 tablespoons dry white wine and cook until mostly evaporated, about 3 minutes. Add the remaining 4 tablespoons unsalted butter. Once melted, add 1/3 cup all-purpose flour and whisk until well combined, 1 to 2 minutes. While whisking constantly, pour in in 3 1/2 cups whole milk. Bring to a boil, whisking occasionally.
13. Reduce the heat to maintain a simmer. While whisking constantly, gradually add the cheese mixture, 1/2 teaspoon kosher salt, and 1/4 teaspoon red pepper flakes. Bring back to a simmer, whisking constantly. Add the pasta and stir until completely coated in the sauce. Add the lobster meat and stir until evenly combined.
14. Transfer the mixture to the baking dish, making sure to scrape in any cheese sauce from the pot, and spread into an even layer. Sprinkle evenly with the Parmesan breadcrumbs.
15. Bake until the breadcrumbs are deep golden brown and the edges are bubbling, 20 to 30 minutes. Let cool for 10 minutes before garnishing with the parsley and serving.