Peel shrimp, leaving tail fans whole. Remove casings if desired.
Mix flour, cornstarch and salt. Add beer, butter and egg yolks, stir everything together to form a lump-free batter.
In a large saucepan, pour 5 cm oil, heat to 190 °C. Pull shrimp through batter one at a time and fry in batches in hot fat.
Drain on paper towels.