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Warm Onion Tart with Thyme

This elegant warm onion tart with thyme is a wonderful way to showcase the natural sweetness of slowly caramelised onions. By gently cooking the onions in butter until they reach a deep mahogany hue, you create a rich, savoury topping that contrasts beautifully with the crisp, buttery layers of golden puff pastry. The addition of fresh thyme brings a woody, aromatic note that elevates this simple vegetarian dish into something truly sophisticated.

Ideal as a refined appetiser for a dinner party or as a quick gourmet snack, these bite-sized tarts are incredibly versatile. Using shop-bought puff pastry makes this recipe both accessible and time-efficient without compromising on flavour or texture. You can prepare the thyme-scented onions in advance and simply assemble and bake the pastry rounds just before your guests arrive for a stress-free hosting experience.

Continue reading below

Ingredients for Warm Onion Tart with Thyme

  • 1 Spanish onion

  • 1 tablespoon unsalted butter

  • 1 tablespoon fresh thyme leaves

  • Salt and freshly ground black pepper

  • 1 sheet frozen puff pastry, thawed according to package directions

Peel and cut the onion in half through the root. Trim the ends and then julienne the onion lengthwise.

Melt the butter in a small sauté pan over medium heat. Add the onion and thyme and cook, stirring occasionally, for 10 to 15minutes or until the onion is a deep golden brown. Season to taste with salt and pepper. Keep warm until ready to serve.

Meanwhile, preheat the oven to 204°C.

Peel and cut the onion in half through the root. Trim the ends and then julienne the onion lengthwise.

Melt the butter in a small sauté pan over medium heat. Add the onion and thyme and cook, stirring occasionally, for 10 to 15minutes or until the onion is a deep golden brown. Season to taste with salt and pepper. Keep warm until ready to serve.

Meanwhile, preheat the oven to 204°C.

Unfold the puff pastry sheet on a lightly floured work surface and turn over to prevent the creases from splitting. Pat down gently to flatten the sheet.

Using a 1-inch round fluted biscuit cutter, stamp out 6 rounds and transfer to an ungreased baking sheet. Bake for 8 to 10minutes or until puffed and golden brown.

Disclaimer

While every effort has been made to ensure the information is accurate and up to date, individual needs may vary and dietary requirements can differ based on personal health conditions. Always check food labels and allergen information before preparing or consuming any recipe. If you have specific health concerns, allergies, intolerances, or are following a medically prescribed diet, seek advice from your GP, pharmacist, or a registered dietitian before making significant changes to your diet or lifestyle.

Article history

The information on this page is peer reviewed by qualified clinicians.

  • 28 Jan 2026 | Originally published

    Authored by:

    UK recipe editors

    Peer reviewed by

    UK recipe editors
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