Preheat oven to 400 degrees. Zest both lemons, keeping the zest of each separated. Slice the ends off of one zested lemon, cut five (¼-inch-thick) slices. Cut the remaining lemon in half.

Add a pinch of sea salt to a pot of boiling water, add the fettuccini, and cook al dente. When the pasta is cooked, use tongs to remove it from the pot and place it in a strainer.

Melt butter over medium heat in a large saute pan. Add olive oil, garlic, rosemary, red pepper flakes, 1 teaspoon sea salt, and ½ teaspoon black pepper, and asparagus. Let sizzle for 3-5 minutes. Remove from heat. Mix in the zest of one lemon, shrimp, and lemon slices. Roast for 15-20 minutes, just until the shrimp are firm, pink, and fully cooked. Squeeze the remaining lemon over the pan and toss in pasta. If the dish is dry, add extra pasta water. Garnish with grated zest of 1 lemon and Pecorino Romano (roughly 1 tablespoon).