Simple Midweek Dinner Idea - Roasted Leek and Mascarpone Filo Tart

Why you’ll love this leek and mascarpone tart

• Big flavour, minimal fuss: slow roasting makes leeks sweet and silky.
• Ultra-crispy pastry: filo gives you that shatter-y crunch without making dough.
• Perfect for entertaining: looks impressive, but it’s genuinely easy.
• Great hot or warm: ideal for lunch, dinner, or a “posh picky bits” moment.

Ingredients

Makes 1 tart (serves 2–4 as a main, 4–6 as a side)

• 3 leeks, halved lengthways
• Large sprig of thyme, leaves only
• 1 lemon, zest only
• 120g new potatoes, finely sliced
• 4 tbsp mascarpone
• 2 tbsp crème fraîche
• 1 clove garlic, finely grated
• 30g Parmesan, finely grated (plus extra to finish)
• 3 sheets filo pastry
• 20g butter, melted
• Olive oil, salt and pepper

How to make slow roasted leek and mascarpone filo tart

1) Slow roast the leeks

1. Preheat the oven to 150°C fan.
2. Lay the leeks cut-side up on a baking tray. Drizzle generously with olive oil.
3. Sprinkle over the thyme leaves and lemon zest. Season well with salt and pepper.
4. Roast for 1 hour, until the leeks are soft and cooked through. Remove and set aside.

2) Parboil the potatoes

1. Add the sliced potatoes to a pan of boiling water and cook for 5 minutes until just tender.
2. Drain, then run under cold water to cool. Set aside.

3) Mix the creamy mascarpone filling

1. Preheat the oven to 170°C fan.
2. In a small bowl, mix together the mascarpone, crème fraîche, grated garlic and Parmesan.
3. Season with salt and pepper and stir until smooth and spreadable.

4) Build the filo tart

1. Line a flat rectangular oven tray with baking paper.
2. Lay the filo sheets on the tray, brushing melted butter between each layer.
3. Spoon the mascarpone mixture into the centre in a rectangle shape, leaving a 1-inch border around the edges.
4. Layer over the sliced potatoes, then lay the roasted leeks across the top.
5. Scrunch and fold the filo border up to make a rustic edge. Brush the edges with any remaining butter.

5) Bake until golden and crisp

1. Bake for 20–25 minutes until the filo is deeply golden and crisp.
2. Finish with extra Parmesan grated over the top and serve warm.

Tips for the crispiest filo tart

• Butter is key: brushing between layers prevents soggy patches and boosts crunch.
• Don’t overload the centre: keep the filling in a thin layer so the filo bakes evenly.
• Roast the leeks fully: that slow roast is what turns them sweet and silky, not watery.
• Slice potatoes thinly: so they cook quickly and layer neatly.

What to serve with leek and mascarpone filo tart

This vegetarian filo tart is brilliant with something sharp and fresh on the side. Try:

• A big green salad with lemon dressing
• Rocket + shaved parmesan + balsamic
• Roasted cherry tomatoes or blistered greens
• Soup (tomato, squash, or a simple pea soup)

Storage and reheating

• Best on the day for maximum crispiness.
• Leftovers keep in the fridge for up to 2 days in an airtight container.
• Reheat in the oven or air fryer at 170°C for 6–10 minutes to re-crisp. (Microwave = sad filo.)

FAQ

Can I make this leek filo tart ahead of time?

You can roast the leeks and prep the filling a day ahead. Assemble and bake just before serving for the crispiest pastry.

Can I swap mascarpone for something else?

Yes — cream cheese works well, or ricotta mixed with a spoon of crème fraîche to keep it creamy.

Is this a good vegetarian tart for a dinner party?

Definitely. It’s a proper “centre-of-the-table” dish that feels fancy but is easy to pull off.

Slow Roasted Leek and Mascarpone Filo Tart (Printable Recipe)

Ingredients

• 3 leeks, halved lengthways
• Large sprig of thyme, leaves only
• Zest of 1 lemon
• 120g new potatoes, finely sliced
• 4 tbsp mascarpone
• 2 tbsp crème fraîche
• 1 clove garlic, finely grated
• 30g Parmesan, finely grated (plus extra to finish)
• 3 sheets filo pastry
• 20g butter, melted
• Olive oil, salt and pepper

Method

1. Heat oven to 150°C fan. Place leeks cut-side up on a tray. Drizzle with oil, add thyme and lemon zest, season, and roast 1 hour. Set aside.
2. Boil potato slices 5 minutes until tender. Drain and cool under cold water.
3. Heat oven to 170°C fan. Mix mascarpone, crème fraîche, garlic and Parmesan. Season.
4. Line tray with baking paper. Layer filo sheets, brushing melted butter between each.
5. Spread filling in the centre (leave a 1-inch border). Top with potatoes then leeks. Scrunch edges up and butter the border.
6. Bake 20–25 minutes until golden and crisp. Finish with extra Parmesan.