Slow-Roasted Tomatoes with Garlic and Fresh Thyme

There is a moment in late summer when the tomato plants seem to conspire against you. One day you are admiring the first blushing fruits, the next you are staring at a colander overflowing with more than you can possibly eat fresh. This is not a problem; it is an opportunity. Across the Mediterranean, home cooks have long understood that a glut of tomatoes is a gift to be stretched through the cooler months. Slow-roasting is the simplest, most rewarding way to do it.

Unlike sun-drying, which demands relentless heat and days of attention, oven-roasting concentrates the natural sugars and deepens the savoury character of tomatoes in a matter of hours. The result is soft, jammy morsels carrying the perfume of garlic and thyme, ready to lift a plain bowl of pasta or a slice of toasted sourdough into something memorable.

Choosing and Preparing Your Tomatoes

Any ripe tomato can be slow-roasted, but the best results come from firm, meaty varieties. Plum tomatoes such as Roma or San Marzano are ideal, as they have fewer seeds and less water. Cherry tomatoes work beautifully too, though they need less time in the oven. If you are using a mix from the garden, sort them by size so they cook evenly.

Wash and dry the tomatoes thoroughly, then halve them lengthways. For larger tomatoes, scoop out the watery seeds and pulp with a teaspoon; this speeds up roasting and intensifies the flavour. Smaller cherry tomatoes can be left whole if you prick them once with a skewer to prevent bursting. Arrange them cut-side up on a large baking tray lined with baking parchment. Do not crowd them—use two trays if necessary, allowing moisture to evaporate rather than steam.

The Aromatic Base: Garlic and Thyme

The magic lies in simplicity, so use the best olive oil you can afford and fresh thyme from the garden or a windowsill pot. Dried thyme will do in a pinch, but fresh sprigs release a resinous, lemony note that dried herbs cannot match.

For every kilogram of prepared tomatoes, you will need:

• 4–6 fat cloves of garlic, peeled and sliced thinly
• A generous handful of fresh thyme sprigs (about 10–12)
• 3–4 tablespoons of extra-virgin olive oil
• 1 teaspoon of flaky sea salt
• A good grinding of black pepper
• A pinch of caster sugar (optional, but helpful if your tomatoes are underripe)

Tuck the garlic slices and thyme sprigs among the tomato halves. Drizzle with the olive oil, then sprinkle over the salt, pepper and sugar. Use your hands to gently rub the oil and seasonings over the cut surfaces. If you have lemon thyme, now is the moment to use it—its citrus edge is wonderful with sweet roasted tomatoes.

The Slow-Roasting Method

Preheat your oven to 120°C (fan 110°C, gas mark ½). This low temperature is key: it coaxes out moisture without scorching the edges. Place the trays in the oven and roast for 2 to 3 hours, depending on size and water content. Cherry tomatoes may be ready in 1½ hours; large plum tomatoes can take up to 3½ hours.

You are looking for tomatoes that have collapsed and shrivelled slightly, with concentrated, sticky juices pooling around them. The edges should be dark and caramelised in places, but not burnt. Check them every 45 minutes, rotating the trays if your oven has hot spots. There is no need to turn them.

For a slightly firmer texture for salads, roast for the shorter time. For a jammy, almost paste-like consistency that melts into sauces, continue until the tomatoes are very soft and the juices have reduced to a syrup.

Storing and Preserving Your Harvest

Once roasted, let the tomatoes cool completely on the trays. They will keep in a sealed container in the fridge for up to two weeks. To extend their life further, pack them into sterilised jars, adding a few fresh thyme sprigs and a sliced garlic clove, then cover completely with olive oil. This preserves them for up to three months in the fridge, and the flavoured oil becomes a treasure in its own right—use it for dressings, drizzling over bread, or finishing a bowl of soup.

For longer storage, freeze the tomatoes in small portions. Spread them on a baking tray to freeze individually, then transfer to freezer bags. They will keep for six months. Alternatively, blitz them into a rough paste and freeze in ice-cube trays for instant flavour bombs.

Growing Thyme Alongside Your Tomatoes

Thyme and tomatoes are natural companions in the kitchen garden. Both thrive in full sun and well-drained soil, and the thyme helps deter certain pests. Plant a few thyme plants near your tomato rows, or keep a pot on the kitchen windowsill for easy snipping. Thyme is a hardy perennial, so with a little shelter it will return year after year, providing fresh sprigs even in winter. A mulch of gravel around the base keeps the foliage dry and aromatic. When you harvest, cut stems in the morning after dew has dried, and avoid taking more than a third of the plant at once.

Ways to Use Slow-Roasted Tomatoes

These little gems are astonishingly versatile. Toss a handful through hot pasta with a splash of the roasting oil, a few torn basil leaves and a crumbling of ricotta salata. Pile them onto bruschetta rubbed with garlic, or fold them into a frittata with spinach and goat's cheese. They add depth to a simple salad of mozzarella, rocket and crusty bread, and they are superb alongside roast chicken or lamb. For a quick supper, stir them into couscous with chopped herbs and toasted pine nuts. However you serve them, you will be glad you made the most of your summer glut.