Preheat and prep: Heat oven to 425°F (220°C). Line a sheet pan with parchment.
Season the sweet potatoes: Toss cubes with olive oil, cumin, smoked paprika, chili powder, garlic powder, onion powder, salt, and pepper. Spread in a single layer.
Roast: Bake for 22–28 minutes, flipping halfway, until edges are crisp and centers are tender.
Warm the beans: In a small skillet, heat the black beans with a splash of water and a pinch of salt for 3–4 minutes, just until warm.
Make the sauce: Whisk tahini, lime juice, maple syrup, garlic, and salt.
Add warm water, 1 tablespoon at a time, until it’s creamy and pourable.
Assemble the base: Add cooked rice or quinoa to bowls. Top with spinach or greens so they gently wilt.
Build the bowl: Add roasted sweet potatoes, warm black beans, cabbage, tomatoes, and avocado.
Drizzle and finish: Spoon the lime-tahini sauce over the top. Add cilantro, pepitas, and a squeeze of lime.
Taste and add a pinch of salt if needed.