Mix sauce ingredients in a bowl: mayonnaise, sour cream, tajín, lime juice, and milk. Set aside.

Season chicken breasts on both sides with salt, pepper, chili powder, cumin, paprika, garlic powder, and oregano.

Heat a skillet over medium heat, add olive oil, and once hot, add chicken. Cook until cooked through (165 degrees), flipping once. Remove to a plate.

To the same skillet, add more oil if needed. Add corn, onion, and jalapeño. Turn heat to high, cover, and sauté until corn is charred and tender, about 4-5 minutes.

Remove from heat and stir in half of the sauce to make a creamy street corn mixture.

Spoon rice into a bowl, top with chicken, a big scoop of street corn, and garnish with avocado, cheese, and cilantro.

Serve with a lime wedge and extra sauce drizzled on top, if desired.