Roast the Vegetables
Preheat the oven to 400°F and line 2 baking sheets with parchment paper. Set aside.
In a large mixing bowl, toss the sweet potato cubes with 1 tablespoon olive oil, 1 tablespoon Massel Vegetable Stock Powder, 2 teaspoons chili powder and 1 teaspoon cumin until the potatoes are completely coated. Transfer to a prepared baking sheet and roast for 25-30 minutes on the centre rack.
Meanwhile, add the prepared kale to the mixing bowl and use your hands to toss with the remaining olive oil, Massel Vegetable Stock Powder, chili powder, cumin and minced garlic. Transfer 1/3 of the kale to the prepared baking sheet and roast with the sweet potatoes for 8 minutes until the leaves are crisp on the edges and starting to wilt.
Transfer the cooked kale to a serving platter, stir the potatoes, then add another 1/3 of the kale leaves to the empty baking sheet and roast for an additional 8 minutes. Complete the steps with the final 1/3 of the kale leaves, stirring the sweet potatoes each time you take out a pan of crispy kale.
Prepare the Polenta
Meanwhile, bring the water and Massel Ultracube stock to a rolling boil. When the cubes are completely dissolved, reduce the heat to medium and add the polenta in a slow and steady stream, whisking constantly.
Cover and cook gently over low heat for 20 minutes, stirring frequently until the polenta is thick and creamy.
Once the polenta has cooked for 20 minutes stir in the milk, Massel Vegetable Stock Powder, nutritional yeast (if using) and black pepper.
Divide the polenta between 4 shallow bowls or plates and top with the roasted kale and sweet potatoes. Serve immediately.