Preheat oven to 400°F (200°C). Wash and dry the sweet potatoes, slice them in half lengthwise, drizzle with olive oil, and sprinkle with salt. Place cut-side down on a parchment-lined baking sheet and roast for 35-45 minutes until tender.

In a skillet, heat 1 tablespoon olive oil over medium heat, then add diced onions and chopped bell peppers. Sauté for 5-7 minutes until tender and fragrant.

Stir in the chosen protein and cook for 5-6 minutes until cooked through. Season with garlic, cumin, chili powder, salt, and pepper. Add spinach and wilt.

Once sweet potatoes are roasted, scoop out some flesh, leaving enough for structure. Mix the scooped flesh into the protein mixture.

Fill each sweet potato half with the protein and vegetable mixture. Optionally sprinkle cheese on top and bake for an additional 10 minutes.

Let the boats cool slightly, then garnish with cilantro, green onions, or guacamole, and serve warm.