More like light, fluffy polenta than potato gnocchi, Roman-style gnocchi is made from semolina, a golden durum wheat flour sold at health food stores and Italian-style delis. It's best made ahead and freezes well.
250g Italian semolina (coarse)
1 tbsp butter, chopped
2 egg yolks, lightly beaten
1 tsp sea salt
100g grated gruyere or parmesan
400g mushrooms, e.g. swiss browns, wiped clean
2 tbsp olive oil
2 tbsp roughly chopped parsley
Sea salt and pepper
8 thin slices pancetta or prosciutto cut into strips
Heat milk and water in a heavy-based pan to just before boil. Reduce heat to very low and slowly add the semolina, whisking constantly.
Swap the whisk for a spoon when mixture thickens and cook for 15 minutes, stirring occasionally.
Remove from heat and beat in butter, then egg yolks, salt and grated cheese, reserving one tablespoon.
Spread mixture on an oiled tray and smooth with a wet palette knife to about one centimetre thick. Leave to cool. Refrigerate for at least two hours or overnight.
Cut into discs with a four-centimetre wide cookie cutter dipped in cold water and arrange four rows of three slightly overlapping discs on a lightly oiled baking dish.
Scatter with remaining cheese.
Heat oven to 200C. Trim mushrooms, thickly slice and toss in olive oil, parsley, salt and pepper.
Put mushrooms and pancetta on top of gnocchi and bake for 15-20 minutes. Use an egg slice to lift on to warm plates and serve.