Boil up plenty of salted water. Knead minced meat, egg, mustard, breadcrumbs, thyme, salt and pepper. Form small balls from the mince with moistened hands.
Peel the carrots, halve them lengthwise and cut into diagonal slices. Cook the pasta in boiling salted water for about 10 minutes. Add carrots and peas after about 5 minutes and cook.
Heat the oil in a coated pan. Fry meatballs in it until crispy. Keep warm. Drain noodles and carrots.
Peel and chop the onion. Heat the fat in the pan. Sauté onion in it, dust with flour and sauté. 1⁄4 l Stir in water and milk, bring to the boil and add stock. Let the sauce simmer for about 5 minutes.
Season to taste with salt, pepper and nutmeg.
Add pasta and vegetables to the sauce. Heat everything and season to taste. Serve with meatballs.