Dice sweet potato into 1/2-inch cubes, toss with 2 tablespoons olive oil, cumin, salt, and pepper, then roast on a sheet pan at 425°F for 15 minutes until tender and caramelized.
While sweet potatoes roast, drain and rinse black beans, then warm them in a saucepan over low heat with a pinch of salt.
Halve avocados, scoop into a bowl, mash with juice of 1 lime, half the cilantro, and a pinch of salt to make a quick crema.
Halve cherry tomatoes and toss with juice of the remaining lime and a pinch of salt.
Assemble bowls with roasted sweet potatoes, warm black beans, cherry tomatoes, avocado crema, and remaining cilantro on top.