SAUCE: In a heavy-bottomed pot over medium heat, melt butter. Add garlic and shallot to butter and cook for 1 minute. Add flour and stir with a wooden spoon until a roux is formed. Gently whisk in milk, 1 cup at a time, being sure to work out any lumps.
Add bay leaf and nutmeg and let slow simmer for 5 minutes on low heat. Stir in cheeses and seasoning and continue cooking and stirring until cheese is completely melted and incorporated.
CRUMB TOPPING: Place all crumb topping ingredients in a food processor and mix on low speed until bacon is fully incorprated.
NOODLES: In a large pot of boiling water (not salted), cook noodles until al dente. Strain noodles from water.
TO ASSEMBLE: Add noodles into sauce with lobster and bacon. Place in a casserole dish and top with crumb mixture. Bake in a 350F oven until crumb topping is golden. Remove from oven and serve.