Wash and dry all produce. Halve, peel, and dice onion. Drain and rinse black beans and corn, keeping them separate.

Melt 2 TBSP butter in a medium pot over medium-high heat. Add onion and cook until softened, 4-5 minutes. Stir in rice, beans, and half the Southwest Spice. Add 3/4 cup water and 1 tsp kosher salt. Bring to a boil. Cover, reduce to a gentle simmer, and cook until tender, about 15 minutes.

Heat a medium pan over high heat. Pat corn dry with paper towels, removing as much moisture as possible. Add corn to pan and cook, tossing occasionally, until lightly charred, 3-4 minutes. Season with salt and pepper.

Cut tomato into small cubes. Zest lime until you have 1 tsp zest; quarter lime. Finely chop cilantro. In a small bowl, toss tomato, corn, remaining Southwest Spice, half the cilantro, half the lime zest, juice from 1 lime quarter, and a large drizzle of olive oil. Season with plenty of salt and pepper.

In a second small bowl, stir together sour cream, remaining lime zest, and a squeeze of lime juice. Season with salt and pepper. Once rice is done, fluff grains with a fork. Stir in half the cheese. Season with salt and pepper.

Divide rice between bowls and top with salsa. Garnish with remaining cheese and cilantro. Dollop with crema and drizzle with hot sauce (to taste). Serve with tortilla chips for dipping and remaining lime wedges for squeezing over.