Preheat the oven to 400°F (200°C).

Gather all your ingredients on the counter.

Unroll puff pastry sheets onto a lightly floured surface and cut into squares about three inches wide.

In a bowl, mix shredded cheddar cheese with a splash of Irish beer and Dijon mustard until combined.

Place a spoonful of cheese filling in the center of each square, fold over diagonally to create triangles, and press edges firmly to seal.

Brush each puff with an egg wash.

Bake for approximately 20 minutes until golden brown.