1. Bring a large pot of salted water to a boil. Cook the fettuccine according to package directions until al dente. Reserve ½ cup of pasta water, then drain and set aside.

2. In a food processor, combine Thai basil leaves, garlic, toasted cashews, Parmesan, lime juice, salt, and pepper. While blending, drizzle in the olive oil until the pesto is smooth. Taste and adjust seasoning.

3. Heat a large skillet over medium heat and add a bit of olive oil. Add the shrimp in a single layer and sprinkle with salt, pepper, and optional chili flakes. Cook for 2 minutes per side or until pink and opaque. Remove from heat.

4. In the same skillet, add the cooked pasta and prepared pesto. Toss well, adding reserved pasta water as needed to loosen the sauce. Fold in the shrimp and mix until everything is coated.

5. Plate the pasta and garnish with extra basil, chili flakes, or Parmesan as desired. Serve immediately while warm.