Believe it or not, I gave one of these sandwiches to a meat-eating friend and he didn’t even realise there was no meat in it — let alone that it was vegan! The thyme in the caramelised onions, the chunky tomato ketchup and the tangy mayo all contribute ‘meaty’ associations when tucking into this meat-free beauty.
- 8 extra-large portobello or flat mushrooms, about 150 g (51⁄2 oz) each, ‘skins’ peeled (see tip)
- 2 tablespoons olive oil, plus extra for drizzling
- 2–3 onions, thinly sliced into rounds 1 tablespoon thyme leaves
- To assemble
- 8 large sourdough slices, or 4 rolls cut in half
- Mayo (page 192)
- rocket (arugula) leaves
- Chunky tomato ketchup (page 226)
Preheat the grill (broiler) to high and line a baking tray with foil. Drizzle the mushrooms on both sides with oil and season with sea salt and freshly ground black pepper. Place the mushrooms on the baking tray and grill for 5 minutes on each side, or until golden and cooked.
If necessary, depending on the size and shape of your bread slices, cut the mushrooms so they’ll fit into each sandwich properly.
Heat the 2 tablespoons olive oil in a large frying pan over medium–high heat. Add the onion and cook for 5 minutes, or until golden, stirring constantly. Reduce the heat to medium, add the thyme and cook for a further 2 minutes. Season with salt and pepper. Lightly toast the bread if desired, or keep it fresh. Lightly spread mayo on each slice of bread, or inside the rolls. Divide the onion, rocket and mushroom steaks among the bottom halves, add a good dollop of chunky ketchup, put the lids on and serve immediately.