Adjust rack to upper position and preheat oven to 425 degrees. Wash and dry all produce. Cut potatoes into 1/2-inch-thick wedges (like steak fries). Finely dice tomato. Roughly chop cilantro.

Toss potatoes on a baking sheet with a large drizzle of oil. Season with salt, pepper, and half the Southwest Spice. Roast in oven, flipping halfway through, until browned and tender, 20-25 minutes.

Meanwhile, in a small bowl, combine tomato, cilantro, and a drizzle of olive oil. Season with plenty of salt and pepper. In another small bowl, stir together sour cream, hot sauce, and a pinch of salt.

In a medium bowl, combine beef, remaining Southwest Spice, and a pinch of salt and pepper. Divide mixture in half, then flatten each piece into a wide, roughly 1/2-inch-thick circle. Divide cheese between the centers of each. Fold edges of meat around cheese, shaping and sealing to create a cheese-stuffed patty. Season all over with salt and pepper.

Heat a large drizzle of oil in a large pan over medium-high heat. Add patties and cook to desired doneness, 3-5 minutes per side. Meanwhile, halve buns and place on a second baking sheet. Toast in oven until lightly browned, 2-3 minutes.

Spread crema onto cut sides of buns. Fill buns with patties and salsa (you may have extra). Serve with potatoes and any remaining salsa on the side.