Preheat your oven to 400°F (200°C). Place the sweet potatoes on a baking sheet, pierce each a few times with a fork to allow steam to escape, and bake until tender, about 45 minutes. The skin should be slightly crisp, and the insides soft when pierced with a fork.
While the sweet potatoes are baking, rinse the quinoa under cold water until the water runs clear, then drain well. Combine the quinoa and water in a medium saucepan, bring to a boil, then reduce the heat to low, cover, and simmer for about 15 minutes, until the water is absorbed and the grains are fluffy. Fluff the cooked quinoa with a fork and set aside.
Meanwhile, chop the kale into bite-sized pieces. Heat one tablespoon of olive oil in a sauté pan over medium heat. Add the kale and sauté for 5-7 minutes until wilted and tender. Season with a pinch of salt and pepper, then remove from heat.
Once the sweet potatoes are cool enough to handle, slice them in half lengthwise. The flesh should be soft and caramelized around the edges, with a slightly crispy skin.
Gently scoop out some of the sweet potato flesh into a bowl, leaving a border to keep the shape intact. Mash this flesh slightly with a fork, creating a soft, creamy consistency. Mix in a pinch of salt and pepper for flavor if desired.
Combine the mashed sweet potato, cooked quinoa, and sautéed kale in a large bowl. Mix thoroughly—this creates a hearty, colorful filling with contrasting textures.
Spoon the mixture back into the hollowed-out sweet potato skins, pressing gently to fill completely and create a mound on top.
Return the filled sweet potatoes to the oven and bake for an additional 15-20 minutes, until heated through and the tops are slightly golden.
Remove from the oven, let cool slightly, and then serve warm. You’ll notice the sweet potatoes are glossy with caramelized edges, the grains are chewy, and the greens are tender yet vibrant.