Chocolate Mocha Meringue Pie

• 9 royal short pastry shell
• 4 egg yolks (beaten)
• 650 ml milk
• 150 gr sugar
• 55 gr semisweet chocolate (chopped)
• 40 gr all purpose flour
• 28 gr butter
• 7 gr instant coffee powder
• 4 gr salt
• 4 gr vanilla extract