Clean and wash the carrots and zucchini and cut them into small cubes. Peel and chop the onion
Heat the fat. Fry the onion, zucchini and carrots in it, turning them over. Deglaze with 3/8 l water and bring to the boil. Stir in stock. Cover and cook for about 7 minutes.
Meanwhile cook the pasta in plenty of boiling salted water for 5-8 minutes until al dente
Add the processed cheese to the vegetables and let it melt while stirring. Refine with sour cream. Bring sauce to the boil. Add sauce thickener and bring to the boil briefly. Season to taste with salt and pepper
Wash the chives, shake dry and cut into fine rolls. Add half of the chives to the cheese sauce
Drain the pasta and arrange on plates with the sauce. Sprinkle with the remaining chives