Keto Zucchini Mozzarella Tomato Gratin

This gratin layers thin zucchini rounds and sliced tomatoes in a 9×13-inch dish with mozzarella, then finishes with a Parmesan crust that bakes bubbly and golden. The vegetables are tossed with olive oil, garlic, oregano and basil first, so every layer is seasoned. The card lists 4 grams of carbohydrates per serving, and the dish makes 6 servings.

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Prep is 15 minutes and the oven time is 30, so it is on the table in 45 minutes. It works as a main course or as a side next to grilled meat or a salad.

What Goes in the Dish

• Zucchini (2 medium): sliced into thin rounds, about ¼ inch thick, so they cook evenly.
• Tomatoes (2 medium): sliced to a similar thickness. They add freshness and a little sweetness.
• Mozzarella (1 cup, shredded) and Parmesan (½ cup, grated): mozzarella gives the creamy melt, Parmesan adds savory depth and the golden top.
• Olive oil (2 tablespoons) and garlic (2 cloves, minced): tossed through the vegetables.
• Dried oregano (1 teaspoon) and dried basil (1 teaspoon), plus salt and pepper: the seasoning. Fresh basil leaves are an optional garnish.

Slicing and Layering

A sharp knife makes the slices even, which is what keeps the zucchini from cooking unevenly. Toss the vegetables with the oil, garlic, herbs, salt and pepper in a large bowl until they are well coated.

Grease the 9×13-inch dish and layer half of the zucchini mixture on the bottom. Scatter half of the mozzarella over it, then add the rest of the zucchini mixture and the sliced tomatoes. Finish with the remaining mozzarella and the Parmesan. Bake at 375°F (190°C) for 25 to 30 minutes, until the cheese is bubbly and golden brown. Let it stand for a few minutes before you serve it, which helps the flavors meld and makes it easier to slice.

Adjusting the Gratin

• Eggplant: use it in place of the zucchini for a meatier texture.
• Heat: add red pepper flakes to the vegetable mixture.
• More vegetables: bell peppers, spinach or mushrooms can go in.
• Different cheese: sharp cheddar or goat cheese can be added to the mozzarella and Parmesan.
• Seasoning: add an extra clove of garlic if you like it stronger.

What to Serve With It

A side salad of leafy greens, cucumbers and avocado with olive oil and a splash of vinegar contrasts with the warm, cheesy gratin. Cauliflower rice or mashed cauliflower makes it a heartier meal. For a drink, sparkling water with lemon or a cup of herbal tea works.

Nutrition per Serving

Each serving has 180 calories, 14 grams of fat (7 grams saturated), 4 grams of carbohydrates, 1 gram of fiber, 3 grams of sugar, 10 grams of protein and 300 milligrams of sodium.

FAQ

Can I make this ahead of time?

Yes. Assemble it in the baking dish a day ahead, cover it tightly with plastic wrap and refrigerate. Bake it straight from the refrigerator, adding a few extra minutes to the baking time.

Can I store leftovers?

Keep them in an airtight container in the refrigerator for up to 3 days. Reheat in the oven or microwave until warmed through.

Can I freeze the gratin?

Yes. After baking, let it cool completely, then wrap it tightly in plastic wrap and aluminum foil. It keeps for up to 3 months. Thaw it in the refrigerator overnight and bake until heated through.

Can I use a different cheese instead of mozzarella?

Provolone, gouda or sharp cheddar all work. They melt a little differently, so choose one you like.

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Written and edited by The Foodie Yummy Kitchen Team

The Foodie Yummy Kitchen Team writes and edits the recipes on Foodie Yummy: classic American potluck salads, holiday sides and easy comfort food, with a few low-carb options. Every recipe lists exact quantities, numbered steps and a printable recipe card, plus notes on swaps, storage and make-ahead timing. Spot a problem with a recipe? Tell us through the contact page and we will correct it. About us