Kale and Sweet Potato--Stuffed Vegan Ravioli

In a medium bowl whisk together spelt flour, potato flour, and 1 teaspoon salt. Add milk; knead just enough to form a ball of dough. (Don't overknead.) Cover dough with a clean, damp towel. Let rest 30 minutes. 2. For filling, in a large skillet combine onion, sweet potato, garlic, rosemary, and ¼ cup water. Cook over medium 10 minutes or until onion turns translucent. Add 1 to 2 tablespoons water, cover skillet, and cook 10 minutes more or until potato is tender, stirring frequently. Stir in kale; cook 5 to 7 minutes more or until kale wilts and any excess moisture is cooked off. Stir in nutritional yeast and season with salt and pepper. Remove from heat; mash filling with a potato masher. Set aside until cool enough to handle. Shape mixture into 20 balls using 1½ teaspoons filling per ball. Place balls on a platter. 3. Bring a large pot of water to boiling. Prepare an assembly line with a large cutting board dusted with spelt flour, a rolling pin, a bowl with the potato starch for dusting, a bowl of water, and a large tray dusted with spelt flour. 4. Knead dough on the prepared cutting board, adding more flour as needed to reduce stickiness. Divide dough into four portions and roll each into a ball. 5. Using a rolling pin, roll a dough ball into a long rectangle at least 4 inches wide and about the thickness of a lasagna noodle. Use a sharp knife or a pizza cutter to trim and straighten edges. Slice the rectangle into 4×2-inch strips. Repeat with remaining dough balls until you have 20 strips. Dust strips with potato starch to prevent sticking. 6. Place a ball of filling on one side of a strip, leaving a ½-inch margin on the three closest edges. Dip fingers in water to moisten dough around filling. Fold the opposite end of the strip over filling, matching the edges and pressing around filling to seal. Crimp edges with the tines of a fork. Place ravioli on flour-dusted tray. Repeat with remaining dough and filling. 7. Using a slotted spoon, add ravioli, a few at a time, to boiling water; start with the first ones assembled. Cook 30 seconds or until ravioli float to the surface. Using a slotted spoon, transfer ravioli to a platter. To serve, divide ravioli among shallow bowls and top with marinara sauce.