Fry the bacon or ham cubes in a pan and place in a bowl. Fry the minced meat in the same pan and season with salt, pepper and oregano.
Peel the potatoes and cut them into medium-thick slices. Pour the whipped cream into a medium-sized saucepan, fill the mug with milk and add. Season to taste with nutmeg, salt and pepper. Add the potatoes and bring the whole thing to a boil. Simmer for 7 minutes, then add the diced bacon or ham and simmer for another 7 minutes.
Preheat the oven to 180 ° C (top / bottom heat). Cut the zucchini into slices and layer in an oiled baking dish. Scatter the vegetable stock on top. Spread the tomato sauce on top with a spoon, then layer the minced meat on top.
Spread the potato and cream mixture on top and cover with cheese. Bake the casserole for 15 minutes at 180 ° C and then cook at 150 ° C for 10 minutes.