Peel and finely dice the onion and garlic. Clean, wash and finely dice the celery. Wash sage, dab dry and remove stalks. Put 5 leaves aside, cut the rest into fine strips.
Clean and wash the peppers, dab dry and cut into fine cubes. Wash the tomato, dab dry and cut into slices. Heat the oil in a pan, fry the minced meat in it, season with salt, pepper and paprika powder.
Add the onion, garlic, diced peppers and celery and fry for approx. 3 minutes. Stir in strained tomatoes, tomato paste and sage. Bring to the boil, cover and braise over medium heat for about 40 minutes, stirring occasionally.
Meanwhile, prepare the pasta in boiling salted water according to the instructions on the packet. Whisk eggs and milk, season with salt, pepper and nutmeg. Drain the noodles and let them drain. Season bolognese with salt and pepper.
Place the pasta and bolognese in a greased casserole dish, pour egg milk over it. Cover the casserole with tomato slices. Cover each tomato slice with 1 sage leaf. Sprinkle the casserole with cheese. Bake in the preheated oven (electric cooker: 200 °C/ convection oven: 175 °C/ gas: level 3) for approx. 45 minutes until the egg milk has completely set.