"Create a detailed recipe for Aguachile Estilo Nayarit with 500 g raw shrimp (peeled and butterfly cut), 10 large limes, 1/2 cup cilantro, 1 garlic clove, 3 serrano chiles, 1/4 purple onion, 1/2 cucumber, salt and pepper to taste, avocado slices (optional), and crispy corn tostadas. Include steps for marinating shrimp in lime juice, making the green chile sauce with serranos, cucumber, garlic, onion, cilantro, lime juice, salt, and pepper, mixing shrimp with sauce and vegetables, refrigerating, and serving with avocado and tostadas. Use imperial units."