Remove the baking sheet and lightly brush each zucchini slice with ketchup (or tomato sauce). I used to cook with kebab ketchup.
Sprinkle with cheese.
Top with a thin circle of sausage and sprinkle with spices to taste: oregano, thyme, Basil or a mixture of them. I have thyme and Basil here.
Put the baking sheet back in the oven for another 5 minutes.