For the spaghetti with radicchio, toast the cashews and sunflower seeds in a dry pan until lightly browned. Allow to cool. Clean and chop the radicchio and green onions.
Finely chop garlic and chili pepper. Cook spaghetti according to package directions. Heat olive oil in a large skillet and sauté onions, garlic, radicchio, chile and maple syrup for a few minutes.
Finely grind cashews, sunflower seeds, yeast flakes and salt in a blender and add to the vegetables in the pan. Drain the spaghetti, mix with the vegetables and season with salt.