Preheat oven to 200 C (390 F) and brush two ramekins with butter or olive oil.
Grate potato, cheese and zucchini. Finely dice onion.
Put a layer of potato about 1 cm thick in the bottom of each ramekin. Add a thin layer of zucchini, then a sprinkle of onion, then a layer of cheese.
Repeat these layers to fill the ramekins, ending with a cheese layer on top.
Pour 1/3 cup of cream over each one.
Bake for about 35 minutes, or until vegetables are tender and top is golden brown.
Let sit for at least 10 minutes until cool enough for your toddler.