2tablespoonsUnsalted Buttermelted or olive oil + 1 tablespoon to grease dish
1cupGrated Mozzarelladivided (or old mature cheddar or Emmental)
Preheat oven to 425°F (220°C). Grease a 1.5-liter square glass or ceramic baking dish with butter. Set aside.
Slice the zucchinis into 1/4 inch thick (0.6 cm), place on a large bowl, sprinkle 1 teaspoon salt all over the slices and toss with your hands to bring the salt in contact with all slices. Set aside 20 minutes. This step will extract the zucchini water and prevent a watery casserole, don't skip!
Drain zucchini slices, then lay the slices onto absorbent paper and pat dry with more absorbent paper to remove as much excess water as you can.
In a large saucepan, melt butter over medium heat and fry onions until fragrant and soft. Stir in garlic, pour heavy cream, sour cream, and keep cooking until it forms bubbles on the sides.
Stir in half of the grated parmesan and half of the grated mozzarella and stir until the cheese is fully melted and it forms a cheesy sauce.
Lay the zucchini slices in a row into the square baking dish. See the picture in my post or watch the video to see how to make this.
Pour the cheese sauce and top of the zucchini and spread evenly to cover all the zucchini slices. Sprinkle the rest of the parmesan and mozzarella cheese all over the zucchini slices.
Bake for 15-20 minutes or until cheese is broiled on top, the sauce bubbles in the pan, and zucchini are tender. Don't overbake, or the zucchini will become mushy.
Store in the fridge in an airtight container for up to 4 days. Rewarm in a saucepan or the microwave.
Freeze in a single-serve airtight container for easy single meal serve. Defrost in the fridge the day before and rewarm in the microwave or saucepan.