Cook pasta in a large pot of generously-salted water until al dente, according to package instructions.Meanwhile, heat butter in a large saute pan over medium-high heat. Add shallot and garlic and saute for 2 minutes, or until fragrant, stirring occasionally. Add shrimp and immediately season (sprinkle) with crushed red pepper flakes, salt and pepper. Continue sauteing the shrimp with the garlic for about 3-4 minutes, or until pink on both sides and no longer opaque.Add in the chicken stock, wine, lemon juice and lemon zest, and stir to combine. Let the mixture continue cooking for an additional minute to boil down, then remove from heat.Drain the pasta, and serve topped with the shrimp scampi. Sprinkle with desired toppings.