In a food processor or blender, add the ingredients listed under “for mango dressing.” Blend until smooth and creamy. Set aside.
In a small bowl, combine the seasonings: chili powder, garlic powder, ground cumin, onion powder, salt, and pepper. Mix well.
Sprinkle half of the prepared seasoning over the shrimp and coat it well with a tablespoon of oil.
Heat a grill pan or outdoor grill over medium heat; add the shrimp and cook for 4-5 minutes until the shrimp is cooked through and has beautiful grill marks. Transfer the grilled shrimp to a plate and set aside.
Sprinkle the remaining half of the prepared seasoning over the sliced onions and bell peppers and coat them well with the remaining tablespoon of oil.
Add the onion and bell pepper mixture to the grill pan and cook for 3-5 minutes, along with the sweet corn on the side of the grill. Once done, set them aside.
On a large serving platter, add the lettuce, grilled shrimp, grilled peppers, grilled corn, sliced avocado, and sliced mango. Drizzle the mango dressing over the salad and toss.
Garnish the salad with lime slices and serve immediately.