Crunchy baked tomato & onion gratin

Crunchy baked tomato & onion gratin

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(12 ratings)

Prep: 25 mins Cook: 1 hr, 20 mins


Serves 6
Simplicity is key to this slowly-cooked vegetarian bake- serve with plenty of bread to mop up the juices

Nutrition and extra info

  • Freezable
  • Healthy
  • Vegetarian
  • Vegan

Nutrition: per serving

  • kcal189
  • fat8g
  • saturates1g
  • carbs24g
  • sugars13g
  • fibre3g
  • protein4g
  • salt0.3g
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  • 3 onions, thinly sliced



    Onions are endlessly versatile and an essential ingredient in countless recipes. Native to Asia…

  • 3 garlic cloves, thinly sliced
  • 4 tbsp olive oil
    olive oil

    Olive oil

    ol-iv oyl

    Probably the most widely-used oil in cooking, olive oil is pressed from fresh olives. It's…

  • 1.2kg mixed tomato, from really big to cherry



    A member of the nightshade family (along with aubergines, peppers and chillies), tomatoes are in…

  • 8 thyme or oregano sprigs, or a mixture, stripped, plus a few more


    This popular herb grows in Europe, especially the Mediterranean, and is a member of the mint…

  • 1 tbsp golden caster sugar
  • 50-85g fresh white breadcrumbs - if you've got a crust, use this so the crumbs are nice and golden


  1. Heat oven to 180C/160C fan/gas 4. Heat half the oil in a pan and gently soften the onions and garlic for 15-20 mins until really soft and sticky but not browned. Put the onions, tomatoes (halve the large ones), herbs, sugar and breadcrumbs in a baking dish, season well and toss together.

  2. Drizzle with the remaining oil, scatter with a few more herb sprigs and bake for 1 hr until going golden on top and the tomatoes are juicy.

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Comments, questions and tips

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Mandy Pargeter Sharp's picture
Mandy Pargeter Sharp
22nd Jun, 2020
Lovely recipe but found it far too sweet with the sugar. Next time I will not add sugar as onions and tomatoes cooked have a sweetness also. I added Parmesan and panko crumbs. Will put less crumbs in as it was a bit stodgy.
13th Mar, 2018
This was ok. Easy to make. I halved the amount for 2 of us, but I think I was too generous with the breadcrumbs as there wasn’t much juice but quite a bit of soggy bread! I added panko and cheese half way through the cooking which was lovely. Served with homemade multi grain bread and some bacon. I would make again.
spacecadetcat's picture
14th Jan, 2018
Delicious! Served mine with penne pasta and garlic bread, turned out to be a really fresh, summery meal and relatively healthy too
12th Aug, 2017
This is so delicious, I love onions, so add a few more than the recipe suggests. About 30 minutes from the end, I top with grated cheddar and panko crumbs - it really is out of this world. With so many delicious recipes from bbcgoodfood, we would rather eat in than out.
Mary Nardo
2nd Sep, 2014
We had so many tomatoes from our garden that were ripe at the same time. I found this recipe and gave it a try. It was delicious. I read the comments about adding pepper so I added a few peppers too. It was easy to prepare and really delicious. We did have French bread with it. I think a little pasta on the side would be great with it as well.
30th Aug, 2013
We had this last night and it was really yummy, and good way to help use up my tomato glut. I had a red pepper which needed to be used, so slice that up and cooked it with the onions and garlic. Also added some black olives when mixing everything together in the baking dish. Served with 3 diffrerant types of homemade tear and share bread to soak up the juices. Will certainly make this again
23rd Aug, 2013
This is really, really nice. I add parmesan to the breadcrumbs, and have also added red peppers to the tomatoes, which was tasty. Next time I might put some olives in with it too.
28th Aug, 2015
Should this be frozen cooked or uncooked? I want to use a glut of tomatoes .
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