- 2 large red onions, peeled and cut in half
- 4 large mushrooms, washed
- 4 tsp olive oil
- salt and pepper to taste
- 4 burger baps
- Preheat the oven to 200 degrees.
- Remove the center core of the onions so that they can fit over the stalks of the mushrooms.
- Place the mushrooms and onion stacks on a baking tray.
- Pour a tsp of olive oil over each one and season with salt and pepper.
- Roast in the oven for 30 to 40 minutes or until the onion is nicely caramelised.
- Serve inside the baps, possibly with some relish or ketchup.