1. Prep a large baking sheet with parchment paper and set aside. Gently roll out both puff pastry sheets (using flour as needed) until roughly 12×14 inches. Place them on top of each other and trim the edges so they’re even. Keep them stacked and cut into 8 equal rectangles.
2. Unstack the pieces and place separated onto your baking sheet. Chill for 15 minutes in fridge while you prep the other ingredients: cut your cheese slices, get the jam ready, and whisk your egg.
3. Take your pastry out of the fridge. Egg wash around the border of half, spread a tablespoon of strawberry jam in the middle of each pastry with the egg wash (leaving the border untouched), and then place your cheddar blocks on top of the jam.
4. Place the other pastry halves overtop, pressing down around the edges to help seal them. With a fork, poke 4 holes in the tops of each (to let steam escape during the bake) and then crimp the edges to further help seal. Trim the edges again if desired for a cleaner look.
5. Chill these in the fridge for another 15 minutes. Then, generously brush each with your egg wash, sprinkle with the sliced almonds, and bake at 400°F (200°C) for 23-25 minutes (or desired browning). Let cool slightly before serving.

These are best enjoyed and served same-day, but will keep at room temperature for a few days stored in an airtight container.