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Roasted Red Onion Flowers

These roasted red onion flowers are a visual triumph that transforms the humble onion into a show-stopping vegan side dish. By roasting the onions whole in their skins, the centres become incredibly sweet and tender, while the outer petals develop delicious crispy edges. Infused with aromatic rosemary, thyme, or bay leaves, they offer a sophisticated savoury flavour that pairs beautifully with almost any main course.

This simple vegetable dish is perfect for a Sunday roast or as a light dinner when served alongside a sharp green salad and some crusty bread or artisanal cheese. It is naturally gluten-free and plant-based, making it a versatile addition to your cooking repertoire. For the best results, use smoked sea salt to enhance the deep, caramelised notes of the onions.

Continue reading below

Ingredients for Roasted Red Onion Flowers

  • 6 medium red onions or sweet onions (such as Walla Walla), skin on, roots intact

  • 6 tablespoons olive oil, divided

  • Salt (smoked is delicious here)

  • Herbs-either a few bay leaves or a few sprigs of rosemary and thyme

  • Freshly ground black pepper

How to make Roasted Red Onion Flowers

Preheat oven to 350°.

Make a total of 4 vertical cuts in each onion to create 8 wedges still attached at the root end.

Drizzle a little of the olive oil into a baking dish, then arrange onions root end down.

Spoon remaining olive oil into and around onions. Sprinkle generously with salt, getting some into the centre of the onions. Toss in herbs.

Roast for 40 minutes. Rearrange onions so that their petals open, and drizzle with a few spoonfuls of the caramelized onion juices from the pan. Roast until onions are tender on the inside with crispy bits on their outer petals, about 20 minutes longer. Season with pepper and more salt to taste. Serve hot or at room temperature as a side dish, or as dinner with a good cheese and a green salad.

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.

  • 16 Jan 2026 | Originally published

    Authored by:

    UK recipe editors

    Peer reviewed by

    UK recipe editors
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