Burn the chillies

• Heat a dry frying pan over high heat.
• Add the chillies and char them until blackened and blistered on all sides.
• Remove from the pan and leave to cool slightly.

Melt the anchovies into the butter

• Lower the heat and add the butter to the pan.
• Add the anchovies and grated garlic and cook gently until the anchovies melt into the butter.

Finish the butter

• Finely chop the burnt chillies and stir them into the butter with the lemon zest and flaky salt.
• Taste and adjust the seasoning.

Set the butter

• Pour the butter into a small dish or roll it in baking paper into a log.
• Chill until firm, then serve on bread, fish or vegetables.