Preheat the oven to 425°F (220°C). Line a baking sheet with parchment paper.

In a medium bowl, toss the sweet potato cubes with olive oil, smoked paprika, cumin, 1/2 teaspoon salt, and black pepper until evenly coated.

Spread the sweet potatoes in a single layer on the prepared baking sheet. Roast for 20 minutes, then flip with a spatula and roast for another 10 minutes, until tender and browned at the edges.

While the sweet potatoes roast, cook the rice. In a medium saucepan, combine rice, 1 3/4 cups water, and 1/2 teaspoon salt. Bring to a boil over high heat, then reduce heat to low, cover, and simmer for 15 minutes. Remove from heat and let sit, covered, for 5 minutes. Fluff with a fork.

In a small saucepan, combine the rinsed black beans, 1/2 cup water, minced garlic, and dried oregano. Bring to a gentle simmer over medium heat. Cook for 5 minutes, stirring occasionally, until the beans are heated through and the liquid has slightly thickened. Season with a pinch of salt.

Make the lime crema: In a small bowl, whisk together sour cream (or Greek yogurt), lime juice, and 1/4 teaspoon salt until smooth. Taste and adjust lime or salt as needed.

Assemble the bowls: Divide the rice among four bowls. Top with roasted sweet potatoes, seasoned black beans, and sliced avocado. Drizzle with lime crema and garnish with fresh cilantro and lime wedges. Serve with hot sauce if desired.