Preheat the oven. Set it to 425°F (220°C). Line a baking sheet with parchment for easy cleanup.
Season the sweet potatoes. In a bowl, toss the cubes with olive oil (or a splash of water/veg broth), cumin, smoked paprika, chili powder, salt, and pepper.
Spread them on the baking sheet in a single layer.
Roast until tender. Bake for 22–28 minutes, flipping halfway. They should be golden on the edges and easily pierced with a fork.
Sauté the veggies. While the potatoes roast, warm a skillet over medium heat. Add onion and bell pepper with a splash of water or a teaspoon of oil.
Cook 5–7 minutes until softened. Add garlic and cook 30 seconds more.
Add beans and corn. Stir in black beans and corn. Season with a pinch of salt and a dash of cumin if you like.
Cook 2–3 minutes, just to warm through.
Make the drizzle. Whisk tahini, lime juice, warm water, maple syrup/date paste, and salt until smooth and pourable. Adjust water as needed.
Warm your base. Heat cooked brown rice or quinoa. A quick steam in the microwave or a covered skillet with a splash of water works well.
Assemble the bowls. Add a scoop of rice or quinoa to each bowl.
Top with roasted sweet potatoes, the bean-corn mixture, avocado slices, and cilantro.
Finish with lime and drizzle. Squeeze lime over the top and add the tahini sauce. Taste and adjust salt, spice, and acidity.