Bring a large pot of salted water to boil. Cook spaghetti until al dente. Reserve ½ cup pasta water, then drain.
In a large skillet, heat butter or olive oil over medium. Add onion/shallot and cook until soft.
Stir in garlic and red pepper flakes for 30 seconds.
Add cherry tomatoes; cook 2–3 minutes until softened.
Toss in langostino tails; cook 1–2 minutes just to warm through.
Add white wine, stir, and let it reduce slightly.
Pour in Trader Joe’s Lobster Bisque, add lemon zest + juice, stir to combine. Simmer gently 1–2 minutes.
Add cooked spaghetti, tossing until evenly coated. Use pasta water to loosen if needed.
Season with salt + pepper. Garnish with Parmesan + parsley or basil. Serve immediately.