Preheat the oven to 180 °C.

NextChop the onion and cook it in a frying pan with a little oil until translucent.

Chop the onion and cook it in a frying pan with a little oil until translucent.

NextCut up the bacon and add it to the pan (with the bacon fat you don't need more oil).

Cut up the bacon and add it to the pan (with the bacon fat you don't need more oil).

NextWhen the bacon is browning, add the mushrooms cut into small pieces.

When the bacon is browning, add the mushrooms cut into small pieces.

NextBeat the egg with the oil and milk, and sift in the flour, baking powder and bicarbonate. Season with salt and pepper and beat well.

Beat the egg with the oil and milk, and sift in the flour, baking powder and bicarbonate. Season with salt and pepper and beat well.

NextAdd the onion, mushrooms, bacon and Parmesan and mix until everything is well combined.

Add the onion, mushrooms, bacon and Parmesan and mix until everything is well combined.

NextDivide the batter between the muffin moulds and sprinkle grated cheese over each muffin.

Divide the batter between the muffin moulds and sprinkle grated cheese over each muffin.

NextBake for about 20-25 minutes.

To make them look like mushrooms, cut a tomato in half, scoop out half a centimetre, put it on top of the muffin and add little rounds of fresh cheese on top.