A dinner in 10 minutes that drove the whole world crazy! Very easy and delicious!

Water
Salt
vegetable oil
300 g kava tappi paste
50g butter
1 leek
4 tablespoons flour
500 ml milk
Salt
black pepper
vegetable oil
1 onion
3 cloves of garlic
3 stalks of celery
400g minced meat
100g mushrooms
Salt
Black pepper
Provencal herbs
140g cheese