Blend together the avocado, basil, lemon juice, garlic, pumpkin seeds, and water. Slowly drizzle in the avocado oil until all the ingredients are combined.
In a large saucepan heat olive oil to medium heat. Add shrimp to pan and sprinkle with cayenne pepper, salt and black pepper. Cook for 2 minutes per side until shrimp are no longer opaque. Remove shrimp from pan.
Smear a generous spoonful of the pesto onto each plate. Place shrimp on pesto and garnish with additional basil, pumpkin seeds, or shredded lettuce.