Preheat the oven to 425°F (220°C).
Toss the cubed sweet potatoes with olive oil, salt, black pepper, paprika, and garlic powder.
Spread evenly on a baking sheet and roast for 25–30 minutes, flipping halfway through, until tender and golden.
Meanwhile, cook the ground beef in a skillet until browned. Drain any excess fat, then stir in the taco seasoning.
In a bowl, combine the corn, red onion, cilantro, sour cream or blended cottage cheese, mayonnaise, cotija, lime juice, and Tajín or elote seasoning.
Divide the roasted sweet potatoes among bowls.
Top with the seasoned taco beef and street corn mixture.
Finish with extra cotija, cilantro, and a squeeze of fresh lime.
