Caramelised Onion and Sweet Potato Galette
This galette is one of those recipes we keep coming back to when we want to make something that looks seriously impressive but tastes even better than it looks. The combination of deeply caramelised onions and tender sweet potato on a buttery, flaky pastry base is just unreal. You get that sweet, savoury richness from the onions, a little earthiness from the sweet potato, and this gorgeous rustic edge where the pastry folds over itself and goes golden. It's the kind of thing you'd be proud to put in the middle of the table. Trust us, make this one tonight and you'll be talking about it for days.
Before You Start
- Preheat oven to 200°C fan
- Large baking tray lined with baking parchment
- Saucepan (medium to low heat)
- Roasting dish
- Mixing bowl
- Microplane (for zesting lemon)
- Plant-based shortcrust pastry — remove from fridge in advance to come to room temperature
Ingredients
- 3 onions
- 1 tbsp olive oil
- 1 tbsp plant-based butter
- 1 tsp salt
- 1 tsp sugar
- 1 tbsp balsamic vinegar
- 4 medium sweet potatoes
- 1 tbsp dried thyme
- 1 tbsp olive oil
- salt and pepper
- 1 sheet of plant-based shortcrust pastry
- handful of parsley
- 1 large garlic clove
- 1 lemon
- 4 tbsp olive oil
- salt and pepper
Method
For the caramelised onions and sweet potato
- Peel and slice the onions
- Heat the olive oil and melt the butter in a saucepan over medium to low heat. Add the onions and stir to coat in the oil and butter. Cook for 10 minutes until they are turning golden. Sprinkle over the salt and sugar. Stir and and then leave the onions to cook for 30 minutes more, stirring occasionally. The trick here is to leave them alone enough to brown, but not too much that they burn. You may need to lower the temperature and add a splash of water of the onions are drying out
- Whilst the onions caramelise, prep the sweet potato
- Preheat the oven to 200*C fan setting
- Peel and slice the sweet potato into slice, about ½ inch thick
- Toss the sweet potato with the thyme, olive oil and a pinch of salt and pepper
- Roast in the hot oven for 15 minutes, until golden on the outside and soft on the inside. Set to one side
For the gremolata
- Roughly chop the parsley (stems included!). Peel and crush the garlic. Zest and juice the lemon
- Add the chopped parsley, crushed garlic, zest and 1 tbsp lemon juice to a mixing bowl. Stir through the olive oil. Taste and season with salt and pepper
Return to the onions
- The onions are caramelised when they are a rich brown colour, and sticky in texture. At this point, add the balsamic vinegar and deglaze the pan
Assemble & bake
- Remove the pastry from the fridge and allow it to come up to room temperature. Cut around the edges of the pastry so that you have a circle shape. Transfer the pastry to a tray line with baking parchment, and spread the carmelised onions over the pastry, leaving a ¼ inch border all the way around. Arrange the sweet potato on the pastry, slightly overlapping, keeping the border clear
- Bake in the hot oven for 20 minutes, until the pastry is cooked through
Time to serve
- Transfer the galette to a serving plate
- Crumble over the plant-based feta and gremolata before serving in the middle of the table
Tips & Variations
- Give the onions time: We can't stress this enough. The caramelisation is what makes this dish. Set a timer, trust the process, and resist the urge to crank up the heat. Low and slow is the move.
- Use cold pastry: When you're working with the galette dough, keep everything as cold as possible. If it starts to feel warm and sticky, pop it back in the fridge for 10 minutes. Cold pastry equals flaky pastry.
- Add a cheesy layer: We love spreading a thin layer of vegan cream cheese or cashew ricotta on the pastry base before adding the toppings. It adds a lovely creaminess and helps everything stick together beautifully.
Why This Works
The trick here is giving the onions the full time they need. We know 30 minutes feels like a lot, but that's where all the magic happens. They go from sharp and raw to this jammy, sweet, deeply flavoured thing that makes the whole galette sing. Don't rush it and don't stir too much, just let them do their thing.