Bill granger's rustic cherry tart...

Ingredients

• 2 1/2 ounces unsalted butter
• 1/3 cup caster sugar
• 3/4 cup ground almonds
• 2 egg yolks
• 1/2 teaspoon vanilla extract
• 1 sheet puff pastry
• 1 egg yolk
• 10 1/2 ounces cherries
• Sugar, for sprinkling
• Whipped cream, for garnish