Creamy Gnocchi with Mushrooms and Leek

Name: Creamy Gnocchi with Mushrooms and Leek
Prep time: 10 min
Cook time: 30 min
Total time: 40 min
Yield: 4
Ingredients: 500 g gnocchi; 250 g small button mushrooms; 1 leek; 1-2 garlic cloves; 1 tub whipping cream 31% (200 ml); 1-2 tbsp butter; 1-2 tbsp plain flour; milk (as needed); ground black pepper (to taste); salt (to taste); Parmesan (for sprinkling)