Oven-Baked Mushroom & Vegetable Frittata

This oven-baked mushroom and vegetable frittata makes the most of fresh produce, pairing a generous portion of mushrooms with zucchini, onion, and sweet capsicum. Searing the sliced mushrooms until deeply browned develops a savory umami base, while chickpea flour forms a custard-like batter that bakes into a firm, sliceable dish without any eggs or dairy.

Using 500g of mushrooms strikes the ideal balance of deep mushroom flavor without overloading the pan with moisture. It slices neatly for meal prep, breakfast, or a light dinner alongside a crisp salad.

Why This Recipe Works

Pre-cooking the vegetables before baking is essential for a firm, sliceable frittata. Browning the mushrooms over high heat cooks off their natural liquid so the batter stays custardy rather than watery. As the chickpea flour batter bakes, its proteins coagulate, producing a tender crumb that sets cleanly as it cools.

Chef's Pro-Tips

• No baking powder? Easy pivots: You can skip the baking powder entirely. The frittata will simply turn out slightly denser and firmer, much like a traditional Spanish tortilla. Alternatively, add half a teaspoon of apple cider vinegar, white vinegar, or fresh lemon juice to the wet batter right before mixing with the vegetables; the gentle acidity reacts with the chickpea flour to provide a subtle lift.
• Do not rush the resting time: Allow the frittata to rest in the pan for 10 to 15 minutes after removing it from the oven. Chickpea flour needs this cooling window to complete its setting process and lose any residual raw taste.
• Sear the mushrooms undisturbed: Let the sliced mushrooms sit undisturbed in the hot skillet for the first 3 to 4 minutes. This produces deep browning and maximizes savory flavor.
• Fresh herbs: Fold in a handful of chopped flat-leaf parsley, fresh dill, or fresh thyme leaves with the sautéed vegetables for an herbal lift.
• Baking dish sizing: Use a 20 to 22cm (8 to 9 inch) oven-safe skillet, pie dish, or square baking tin. A wider dish will yield thinner slices, so reduce the baking time by 5 to 10 minutes.

1. Preheat and prepare the pan: Preheat your oven to 190°C (375°F). Lightly grease a 20 to 22cm oven-safe skillet or baking dish with a little olive oil.
2. Brown the mushrooms: Heat 1 tablespoon of olive oil in a large frying pan over high heat. Add the sliced mushrooms. Cook undisturbed for 3 to 4 minutes to develop a deep brown crust, then stir and cook for another 4 minutes until their released liquid completely evaporates. Transfer the mushrooms to a bowl.
3. Sauté the remaining vegetables: Lower the heat to medium. Add the remaining 1 tablespoon of olive oil to the pan. Sauté the diced onion, capsicum, and zucchini for 5 to 6 minutes until softened and translucent. Remove from the heat.
4. Whisk the batter: In a large bowl, vigorously whisk together the 120g chickpea flour, nutritional yeast, baking powder (or vinegar if using), turmeric, salt, black pepper, and 300ml water until completely smooth.
5. Combine: Stir the browned mushrooms and sautéed vegetables into the chickpea batter until everything is evenly coated.
6. Bake: Pour the mixture into your prepared skillet or baking dish. Spread the vegetables into an even layer with a spatula. Bake for 30 to 35 minutes, until the center feels firm and the edges turn golden brown.
7. Rest and serve: Let the frittata cool in the pan for 10 to 15 minutes. This resting step is essential for the chickpea flour to fully set and slice cleanly. Cut into wedges or squares and serve warm or at room temperature.