Roast the garlic

• Slice the tops off the garlic heads and set them on a piece of foil.
• Drizzle with olive oil, wrap loosely and roast until the cloves are sweet and soft.

Brown the butter

• Melt the butter in a saucepan over medium heat.
• Keep cooking, swirling, until the milk solids turn golden and it smells nutty.

Squeeze in the roasted garlic

• Let the brown butter cool slightly, then squeeze the soft roasted garlic cloves into it.
• Mash the cloves into the butter.

Whip the butter

• Transfer to a bowl and whisk until pale, creamy and fluffy.
• Season with salt to taste and serve.