Start by cleaning the shrimp under cold water, then pat them dry. In a large bowl, toss the shrimp with olive oil, chili powder, cumin, garlic powder, salt, and pepper until they are evenly coated. Let the shrimp marinate for about 10 minutes.

Preheat your grill or a non-stick skillet over medium-high heat. Once the surface is hot, add the marinated shrimp in a single layer. Cook the shrimp for 2-3 minutes on each side until they turn pink and curl slightly. Remove them from the heat and set aside to rest.

In a mixing bowl, combine the diced avocado, corn, finely diced red onion, chopped cilantro, lime juice, and a sprinkle of salt. Gently stir the mixture to combine, being careful not to mash the avocado.

In another bowl, whisk together the plain Greek yogurt, mayonnaise, minced garlic, lime juice, and milk until smooth. Adjust the milk as needed to reach your desired sauce consistency.

To build your Grilled Shrimp Bowl, begin by dividing the cooked rice among serving bowls. Top the rice with grilled shrimp, a spoonful of avocado corn salsa, and finish with a drizzle of the creamy garlic sauce.