Preheat oven to 425°F. Toss potatoes with oil and seasonings. Spread in a single layer on a baking sheet.
Roast for 28 to 32 minutes, flipping once at halfway, until golden and crispy at the edges.
Brown ground beef in a skillet over medium-high. Drain fat, add spices and tomato paste, stir well.
Add water and simmer 2 to 3 minutes until sauce clings to the meat.
Warm black beans with a pinch of salt and cumin.
Build bowls with crispy potatoes at the base, then taco meat, cheese, beans, corn, salsa, avocado, sour cream, cilantro, and lime.