Soak the thinly sliced potatoes in water to remove excess starch. Drain and pat them dry.
Preheat the oven to 180 degrees Celsius.
In a skillet, melt butter and sauté minced garlic until fragrant. Add sliced onions and sauté until softened. Set aside.
In a greased cake tin, arrange half of the sautéed garlic, onions, and cherry tomatoes.
Place a layer of the sliced potatoes on top. Sprinkle the layer with salt, pepper, dried rosemary, and half of the grated cheese.
Repeat the layering process.
Pour the fresh cream over the top layer of potatoes.
Bake in the preheated oven for 30 to 40 minutes or until the top is golden brown.
Allow the savory cake to cool before loosening its edges with a knife.
Turn the cake upside down onto a platter to serve.