Melt butter in a medium saucepan over medium heat. Stir in risoni and garlic, and saute until lightly browned. Place potatoes, carrot and onion in the saucepan. Continue to cook and stir until tender. Season with dried Italian seasoning, salt and pepper.
Mix water into the saucepan. Stir in vegetable stock cube until dissolved. Cover, reduce heat and simmer 12 minutes, or until risoni is tender and most of the liquid has been absorbed. Top with Parmesan cheese to serve.