4 large flat mushrooms
½ red onion, finely chopped, plus slices to serve
1 clove garlic, crushed
1 tsp sweet smoked paprika
2 tsp thyme, chopped
30 g fresh breadcrumbs
1 tbsp tomato sauce (ketchup), plus extra to serve
2 brioche or other burger buns
Lettuce, sliced gherkins, mustard and fries, to serve
- Remove the stalks from the mushrooms, finely chop, and put in a frying pan with the chopped onion, garlic and ½ tbsp oil. Cook gently until softened, then add the paprika and thyme, and cook for another minute. Tip into a bowl with the breadcrumbs and 1 tbsp of sauce, season and mix well.
- Heat oven to 200C/fan 180C. Brush the caps of the mushrooms with olive oil and heat a chargrill or frying pan. Char the mushrooms on both sides until golden and softening, but not collapsing. Divide the breadcrumb mixture between 2 of the mushrooms, and put the other mushrooms on top, like sandwiches. Put in a roasting tin and bake for 5 minutes or until piping hot, while you get your burger fillings and sides ready. Open the buns and add them to the oven for another 5 minutes with the mushrooms.
- Sandwich the double mushrooms between the toasted buns with the lettuce, sliced red onion, gherkins, mustard and more tomato sauce. Serve with fries, if you like.