Bring a large pot of salted water to a boil and cook spaghetti to 1 minute less than package instructions. Drain spaghetti, reserving one cup of the pasta water.
Meanwhile, in a large skillet, heat olive oil and add the white parts of the scallions, the peppers, Cajun seasoning, and the lime. Stir and cook until the peppers start to soften; about 5 minutes. Add the garlic, stir and cook for about 1 minute then add the tomatoes. Season with salt and pepper, stir, and let the sauce simmer for about 10 minutes. Add the crab and shrimp and cook until the shrimp are opaque; 3-5 minutes. Taste and adjust the sauce adding more Cajun seasoning or salt to taste.
Add the pasta to the sauce and toss to coat. If the sauce is too thick, add the reserved pasta water as needed to loosen. Garnish with parsley, the remaining scallions and serve with lime wedges.
Enjoy!
Keyword cajun pasta, crab pasta, Seafood pasta, shrimp pasta