Vegetable Tian | Recipes

Ingredients

• 3 tablespoonsgood olive oil, plus extra for the baking dish
• 2 largeyellow onions, halved and sliced
• 2garlic cloves, minced
• 454 g (1 pound)medium round potatoes, unpeeled
• 340 g (¾ pound)courgette
• 567 g (1¼ pounds)medium tomatoes
• 1 teaspoonkosher salt
• ½ teaspoonfreshly ground black pepper
• 1 tablespoon, plus extra sprigsfresh thyme leaves
• 57 g (2 ounces)Gruyère cheese, grated

Instructions

1. 1

   Preheat the oven

   Heat the oven to 190°C (375°F).

2. 2

   Cook the onions

   Brush a 33 × 23 × 5 cm (9 × 13 × 2-inch) baking dish with olive oil. Warm 2 tablespoons of olive oil in a medium sauté pan over medium-low heat. Add the onions and cook for 8–10 minutes, until translucent, then stir in the garlic and cook for 1 minute. Spread the onion mixture across the bottom of the dish.

3. 3

   Layer and bake

   Cut the potatoes, courgette and tomatoes into 6 mm (¼-inch) slices. Arrange them alternately over the onions, fitting them closely in a single layer. Sprinkle with the salt, pepper, thyme leaves and thyme sprigs, then drizzle with 1 tablespoon of olive oil. Cover with foil and bake for 35–40 minutes, until the potatoes are tender. Remove the foil and thyme sprigs, scatter the Gruyère over the vegetables and bake for another 30 minutes, or until browned. Serve warm.

What is a vegetable tian?

A tian is a French Provençal dish named after the shallow earthenware dish traditionally used to bake it. The name is also used for layered preparations of seasonal vegetables.

This version combines potatoes, courgette and tomatoes over a bed of softened onion. Thyme and a browned Gruyère topping bring savoury depth to the vegetables.

Nutrition and macros by portion

The nutrition label shows one serving as written: 275 calories, 11g protein, 37g carbs, 11g fat.

The potatoes provide most of the carbohydrates, while the olive oil and Gruyère contribute much of the fat; the cheese also supplies most of the protein. For a more balanced plate, serve a moderate portion with a protein-rich main and a fresh green salad.

Build flavour from the base

Onions: cook them gently until translucent, rather than rushing them over high heat. They form a soft, sweet layer beneath the vegetables.

Garlic: add it only after the onions have softened and give it a minute in the pan. This gives it time to release its aroma without burning.

Slice and layer evenly

Even slices: cut the potatoes, courgette and tomatoes to roughly 6 mm thick so they cook at a similar pace. A sharp knife helps keep the rounds neat.

Close fit: alternate the slices and nestle them snugly into one layer. This keeps the vegetables upright and lets them cook together rather than leaving gaps.

Check the potatoes first

Covered bake: the foil traps steam while the vegetables soften. After 35–40 minutes, test a potato slice with a knife; it should be tender before you add the cheese.

Uncovered finish: baking for another 30 minutes lets excess moisture evaporate and gives the Gruyère time to brown. Remove the thyme sprigs before adding the cheese.

Choose ripe, firm vegetables

Tomatoes: use medium tomatoes that are ripe but still firm enough to slice cleanly. Very soft tomatoes can release more liquid into the dish.

Potatoes: medium round potatoes work well sliced with their skins on. Leave the courgette unpeeled as well, so the alternating layers hold their shape.

Serve it warm

The tian is at its best warm, when the vegetables are tender and the cheese is still soft. Let it stand briefly after baking so the layers settle for serving.

Serve it alongside roast chicken, grilled fish or a crisp green salad. Crusty bread is handy for soaking up the juices.

Recipe notes & tips

• Use a mandoline carefully if you want especially even vegetable slices.
• Keep the onion heat at medium-low so it softens without taking on too much colour.
• Pack the vegetable rounds closely, but keep them in a single layer as directed.
• Cover the dish snugly with foil to help the potatoes cook through during the first bake.
• Check a potato slice for tenderness before uncovering the dish.
• Let the tian rest briefly after baking so it is easier to serve.

Variations

• Add aubergine: replace some of the courgette with thinly sliced aubergine.
• Change the cheese: use another good melting cheese in place of Gruyère.
• Add herbs: include a little chopped fresh rosemary alongside the thyme.
• Make it vegan: omit the Gruyère and finish with a savoury plant-based topping.
• Add chilli: scatter a pinch of chilli flakes over the vegetables before baking.

Common mistakes to avoid

• Burning the garlic: add it after the onions have softened and cook for just 1 minute.
• Uneven slices: cut the vegetables to a similar thickness so they finish cooking at about the same time.
• Crowded layers: keep the vegetables in one layer; use a larger baking dish if needed.
• Skipping the tenderness check: test a potato before removing the foil, and continue baking if it is still firm.
• Adding cheese too early: wait until the covered bake is complete so the topping can brown during the final 30 minutes.
• Using loose foil: cover the dish securely during the first bake to retain steam.

How to store

Cool leftovers, cover and refrigerate for up to 3 days. Reheat in a 180°C oven until hot throughout, covering loosely with foil if the cheese is browning too quickly.

Frequently asked questions