Potato and zucchini frittata
This frittata is close kin to a Spanish tortilla: cubes of potato and soft onion held together by egg, plus thin zucchini and a melted cheddar top. It's made start to finish on the stovetop, with no oven and no nervous flip, and gives two people 25 g of protein each.
- 30 minTotal time
- 2Servings
- 480kcal / serving
- 25 gProtein
It's built to slice cleanly and travel, so it works as dinner tonight and lunch tomorrow. The secrets are an egg mix with no added milk, a pan that's the right size, and a loosened edge before it slides out.
The science: why this works
- Ten minutes in the pan with the potato isn't wasted on the onion. As it softens, heat breaks down its sharp sulphur compounds and lets its sugars brown a little, so it ends up sweet and mellow.
- The egg mix has no milk or cream, only pepper. Without extra water to get in the way, egg proteins bond into a firmer network, which is why this frittata slices cleanly and holds up in a lunch box.
- Zucchini is about 95% water. Thin slices cooked for 3 minutes lose some of it to the hot pan, and their pectin softens, so they melt into the egg instead of releasing puddles later.
- The cheddar on top melts under the lid into a cap. Its fat slows evaporation from the surface, so the top stays tender while the egg underneath finishes.
- A frittata is safely done when the centre reaches 71°C (160°F). Carryover heat keeps firming it for a minute or two after the pan comes off the stove.
Why the potato cooks first
Potato takes much longer to soften than zucchini or egg. Cooking it for 10 minutes before anything else lets it become tender. Cutting it small and even helps all the pieces cook at the same speed.
Learn: Cut food the same size →Why the frittata cooks on low with a lid
Low heat sets the egg gently so the frittata stays tender and does not burn on the bottom. The lid traps steam, which cooks the top without needing a flip. After 10 minutes the middle is fully set.
Learn: Cook eggs gently →Why waxy or all-purpose potatoes work well
Waxy potatoes hold their shape when cooked, so the pieces stay intact in the egg. Floury potatoes can crumble and turn mushy. A firm, creamy bite makes the frittata better.
Learn: Waxy and floury potatoes →Potato and zucchini frittata
30 minutes · 2 servings · Italian · Dinner
Ingredients
Makes 2 servings
Method
Tips for the best result
- Use a 24 cm (9 to 10 in) non-stick pan for 5 eggs. It gives a frittata about 2.5 cm thick, which sets in 10 minutes.
- Shake the pan right after pouring in the egg so it settles into every gap.
- No lid that fits? A large plate or a baking sheet works in a pinch.
- Run a silicone spatula all the way around the edge, then shake the pan, before sliding the frittata onto the board.
- Leave it at room temperature for 15 to 20 minutes before eating cold slices. Flavours taste fuller when it's not fridge-cold.
- Chef Fizz's rule: give the pan a wiggle. If the middle ripples like a waterbed, it needs two more minutes.
Mistakes to avoid
- Using a huge, seedy zucchini — the frittata weeps. Pick a small or medium one and slice it thin.
- Beating the eggs to a froth — the bubbles rise and leave a spongy, holey top. Beat just until the colour is even.
- Pouring egg into a dry pan — the potatoes soak up the oil and the egg welds to the base. Add another teaspoon of oil first if the pan looks dry.
- Cooking five eggs in a 30 cm pan — it ends up thin and rubbery. Use a smaller pan so the frittata is thick and tender.
Variations and swaps
- If your pan is ovenproof, finish it under a hot grill (broiler) for 2 minutes for a puffed, browned top.
- Leave out the cheese and use a little extra olive oil for a dairy-free frittata.
- Tear a few basil or mint leaves into the egg for a fresh, summery version.
- Swap the cheddar for smoked mozzarella or Gruyère.
- Add 50 g of chopped ham or chorizo with the zucchini (no longer vegetarian).
- Swap zucchini for bell pepper or spinach, cooking spinach until it is wilted first.
Storing and reheating
Cool the frittata and refrigerate within 2 hours, wrapped, at 4°C (40°F) or below, for 3–4 days. Cut it into wedges before chilling so lunches are grab-and-go. For warm slices, reheat in a covered pan over low heat with a teaspoon of water, or in a 180°C (350°F) oven for about 10 minutes, until steaming at 74°C (165°F); the microwave works but toughens the edges. You can freeze wedges at −18°C (0°F) for up to 2–3 months, but expect the potato to turn grainy. Always thaw them in the fridge.
Potato and zucchini frittata: questions
What size pan do I need for a 5-egg frittata?
A 24 cm (9 to 10 in) pan is ideal. Smaller makes it too thick to set in the middle; larger makes it thin and rubbery.
How do I stop my frittata sticking?
Use a non-stick pan, make sure there's still a thin film of oil after the potatoes cook, and loosen the edges with a spatula before sliding it out.
Can I use leftover cooked potatoes?
Yes. Dice them and fry them with the onion for 4 to 5 minutes, just long enough to soften the onion and warm the potato through.
What's the difference between a frittata and a Spanish tortilla?
A Spanish tortilla is mostly potato and onion bound with egg, usually flipped halfway. A frittata often adds other vegetables or cheese and is finished under a lid or in the oven, like this one.
Is this frittata gluten-free?
Yes. Potato, onion, zucchini, eggs, cheddar, olive oil and seasoning are naturally gluten-free. If you're cooking for someone with coeliac disease, check the cheese label to be sure.
Can I freeze frittata?
You can, wrapped in slices for up to 2–3 months, though the potato turns a little grainy. Thaw in the fridge and reheat until steaming.
Can you make a frittata without an oven?
Yes, this recipe cooks entirely on the stovetop. A lid traps steam and sets the top of the eggs on low heat. No flipping or oven is needed.
How do you know when a frittata is done?
The center should be firm, with no liquid egg on top, and the edges pulled slightly from the pan. A knife poked in the middle should come out clean. This takes about 10 minutes on low.
Why is my frittata watery?
Zucchini and other vegetables release water as they cook. Cook them until soft and let extra liquid evaporate before adding the egg. Also be sure to cook the egg until fully set.
Can I eat frittata cold?
Yes, frittata is delicious cold or at room temperature. Keep it in the fridge until you are ready to eat and finish within 4 days. It packs well for lunch.
