1. To make the dressing, put one-fourth of the mango, the oil, vinegar, lime juice, fish sauce, and chile paste in a blender and process until smooth. You should have 1 cup; set aside.
2. Place the shrimp, lettuce, peas, green onions, avocado, tomatoes, remaining mango, lime zest, basil, mint, and cilantro leaves in a large bowl. Toss the salad with just enough of the dressing to coat well. Reserve the rest for another use; it will keep refrigerated for up to 1 week.