To make the pesto. In a food processor, combine the basil, arugula, jalapeño, 1 clove of garlic, the nuts, parmesan, and 1/4 cup olive oil. Season with salt. Pulse until a sauce forms, adding 1-2 tablespoons water if needed to thin.Bring a large pot of salted water to a boil. Add the pasta and cook according to package directions until al dente. Just before draining, remove 1/2 cup of the pasta cooking water. Drain and add the pasta right back into the hot pot.Add the pesto and coconut milk, tossing to combine. Thin the pasta as desired with the reserved pasta cooking water. Meanwhile, make the shrimp. Heat the olive oil in a large skillet over medium heat. Add the butter, shrimp, cajun seasonings, and a big pinch of pepper. Cook on both sides until seared, about 2-3 minutes per side. Stir in the garlic, cook until fragrant. Remove from the heat, stir in the lemon juice. Toss the shrimp with the pasta. Grab a fork and enjoy!