Preheat the oven to 425 degrees.
Wash all your produce. Rinse the black beans in a colander.
Dice the sweet potato and bell pepper into 1/2 in pieces, then toss in a bowl with a drizzle of olive oil and 2 teaspoons of taco seasoning.
Dump the veggies onto a baking sheet, spread them out, and place in the oven on the middle rack. Roast at 425 for 20-25 minutes, or until sweet potato pieces are tender.
While veggies are roasting, add corn and black beans to a skillet. Toss with taco seasoning and a tablespoon of water. Heat over medium until heated through.
In a bowl, mix together sour cream, cumin and 1 tablespoon lime juice.
Stir, and add more lime juice if necessary until you reach your desired flavor. Season with salt and pepper.
Heat tortillas in the microwave or in a warm skillet. Top with a spoonful of sweet potato/bell pepper mixture, a spoonful of black bean/corn mixture, and a dollop of cumin-lime crema. Add any other desired toppings and serve!