Preheat the oven to grill.

Remove the stem of the mushrooms. Slice bocconcini, roughly chop basil and finely slice chilli.

Brush the mushrooms with olive oil and sprinkle over oregano. Place in the oven to grill for 5 minutes or until just starting to soften

Top the mushrooms with tomato paste, followed by bocconcini and chilli. Return to the oven to grill until the cheese is melted and bubbling. Top with basil and serve immediately.