Polish open mushroom and cheese baguette (Zapiekanka)

1. Finely dice the mushrooms and onion.

2. Melt the butter in a frying pan and soften the onion over medium heat for 3 minutes; add the mushrooms and fry over high heat for 8-10 minutes until all their liquid has evaporated – season with salt and pepper.

3. Preheat the oven to 220 °C (even better with the grill function). Halve the baguettes lengthwise and across, giving 8 long open half-baguettes.

4. Spread the mushroom filling evenly over the cut sides and sprinkle generously with grated cheese.

5. Bake for 8-10 minutes until the cheese is melted, bubbling and golden in spots and the edges of the baguette are crisp.

6. Serve piping hot, drizzled with stripes of ketchup and sprinkled with chopped spring onion.

Tip: Zapiekanka was the street food of the 1970s Polish housing-estate era and is today the cult late-night snack of Kraków's Kazimierz district – the classic version needs nothing more than mushrooms, cheese and ketchup.