For the pesto, peel garlic, cut sweet potato into pieces, juice lemon and roughly chop walnuts.
Puree sweet potato, garlic, lemon juice and walnuts with salt and a little pepper in a high container with a hand blender. Meanwhile, slowly add the olive oil until you get a creamy consistency. Add salt and pepper. Wash the zucchini, cut off the ends and cut into long strands with a spiral slicer. Cut cheese into even cubes. Mix zucchini noodles with pesto and serve sprinkled with cheese cubes.