Pre-heat the oven to 180 degrees C
1. Cut each peach in half, removing the stone: hold the peach in one hand and run a small sharp knife around its natural line - I find it easier to hold the knife still and rotate the fruit. Twist in opposite directions then gently pull apart. Using the tip of the knife, carefully ease the stone loose and remove. Place the halves, cut side uppermost in a single layer in an oven proof dish.
2. Cream together the butter and sugar. One at a time add the egg yolks, beating well after each addition followed by the crumbled amaretti biscuits and chopped mint if you are using.
3. Evenly divide the creamed mixture into 16 pieces and roll into balls. Press each ball into the centre of each peach, drizzle with tequila and bake for about 25 minutes until the peaches are just cooked.
Serve chilled with crème or ice-cream.