- 4 portobello mushrooms, stalks trimmed
- 2 sprigs fresh thyme, leaves separated
- olive oil
- the green part of one scallion (spring onion), finely chopped
- sea salt and freshly ground black pepper
- 1 egg yolk
- 1 garlic clove
- a pinch of salt
- 1 tablespoon lemon juice or vinegar
- 3 slices serrano ham, roughly chopped
- 2/3 cup mild olive oil
- Place the mushrooms on a roasting tray and sprinkle with sea salt, a bit of black pepper, the fresh thyme leaves, and a drizzle of olive oil
- Place in a cold oven and set the temperature to 350 degrees F. Bake for 15 minutes.
- Meanwhile, for the ham mayonnaise, blend the egg yolk, garlic clove, salt, lemon juice, and ham in a food processor and then start to add the oil in a steady stream until you have a mayonnaise.
- Remove the tray from the oven and sprinkle the mushrooms with the chopped spring onion.
- Top with a dollop of the ham mayonnaise and return to the oven for a good 5 minutes, or until the top has nicely browned.