Mushroom croquetas

Step 1: Melt 2 ⅛ oz butter with 2 tbsp olive oil in a wide pan over a medium heat. Add 1 onion and cook gently for 5 minutes, until soft and translucent but not browned.

Step 2: Add 10 ½ oz mixed mushrooms (chestnut, shiitake, oyster or wild), 1 clove garlic and ⅓ oz dried porcini, turn the heat up to medium-high and cook for 6–8 minutes, until the mushrooms have released their water, it has evaporated and they smell nutty.

Step 3: Turn the heat to medium-low, sprinkle in 3 ⅛ oz plain flour and stir constantly for 2 minutes. It should look like damp sand and smell toasty, not raw.

Step 4: Add 3 ¼ cups whole milk a ladle at a time (with the porcini soaking water, if using, strained), beating hard after each addition so no lumps form. Season with 1 pinch ground nutmeg, 1 tsp salt and ¼ tsp black pepper.

Step 5: Keep cooking over a low heat, stirring and scraping the bottom with a wooden spoon, for 10–15 minutes, until the béchamel is very thick, glossy and comes away from the sides of the pan in a ball. A spoon drawn through it should leave a clear trail.

Step 6: Spread the mixture in a shallow dish, press cling film right onto the surface to stop a skin forming and leave to cool. Chill for at least 1 hour (or overnight) until firm enough to shape.

Step 7: Set out three plates: the chilled filling, 2 eggs and 5 ½ oz fine dry breadcrumbs. With two spoons or lightly oiled hands, shape heaped tablespoons of filling into small logs about 5 cm long; you should get about 24.

Step 8: Roll each croqueta in egg, then breadcrumbs, pressing the crumbs on so there are no gaps. Any gap lets the filling burst in the oil. Chill for 15 minutes; or freeze them now on a tray, then bag them up.

Step 9: Heat 2 ½ cups olive or sunflower oil in a deep pan to 350°F (a cube of bread browns in 30 seconds). Fry 5–6 croquetas at a time for 2–3 minutes, turning, until deep golden all over. Don't crowd the pan, or the oil cools and they split. Fry frozen ones straight from the freezer for 4 minutes.

Step 10: Drain on kitchen paper and rest for 2 minutes before serving; the inside is molten and very hot.