Grate the cheese, put 2-3 tablespoons of parmesan aside for sprinkling. Cook the pasta in plenty of boiling salted water for about 10 minutes. Drain the jalapeños well. Peel and finely dice onions.
Heat 50 g butter. Sauté onions in it until transparent. Sprinkle with flour and sauté. Stir in milk, bring to the boil and simmer for about 5 minutes. Melt cheese in the sauce while stirring. Season sauce with salt, pepper and mustard.
Drain the pasta and add to the sauce with jalapeños. Place them in a greased dish and sprinkle with Parmesan cheese. Bake in a preheated oven (electric oven: 175°C/circulating air: 150°C/gas: level 2) for about 20 minutes until golden brown.
For the salad garnish: mix vinegar, salt, pepper and 1 pinch of sugar. Fold in the oil. Peel and wash the carrots and cut them into sticks. Clean, wash and chop the peppers. Clean and wash the radishes.
Wash and peel the cucumber and cut in half lengthwise. Cut both into slices. Wash salad and pluck into bite-sized pieces. Mix everything with marinade and serve with the casserole. Drink tip: ice-cold cola.