Rinse arugula, remove tough stems and shake dry. Save some leaves for garnish.
Sweat shallot in butter in a pan until translucent. Add pressed garlic, deglaze with broth and cream and pour in potato cubes. Bring to a boil, add the arugula and cook. Place in a blender and puree. Season with salt and pepper. Place soup in bowls. Peel parmasan with a vegetable peeler. Garnich with arugula leaves.