Portuguese garlicky spinach purée (Esparregado)

1. Wash the spinach and blanch in boiling salted water for 1-2 minutes, then drain, rinse under cold water and squeeze out thoroughly.

2. Chop the spinach very finely with a knife or in a food processor.

3. In a pan, fry the crushed garlic in the olive oil for 1 minute until fragrant but not brown.

4. Stir in the flour, cook for 30 seconds, then add the spinach and pour in the milk.

5. Cook, stirring, for 3-4 minutes until you have a creamy, thick purée; finally stir in the wine vinegar and season with salt and pepper.

6. Serve warm as a side dish with fried fish, pork or salt cod.

Tip: Traditionally it's thickened without milk, just with olive oil and breadcrumbs – the touch of acidity from the vinegar gives esparregado its characteristic fresh flavour.