Shrimp and lump crab in a creamy homemade cajun Alfredo sauce over pasta For the alfredo sauce, I chop and saute red and green bell peppers, half of an onion, 1 celery rib in a little butter, 1 TBSP of Cajun seasoning and 3 cloves of chopped garlic, and sauteed vegetables, and 3 tablespoons of flour