Poach the salmon fillets in boiling water for 5 minutes, then drain them.

Bring the vegetable broth to a boil.

Cook the rice in the broth for 15 minutes.

Hard-boil the 4 eggs.

Thaw the spinach in a saucepan.

Peel the eggs.

Drain the rice and mix it with the chopped herbs.

Place one sheet of puff pastry on a baking sheet lined with parchment paper. Overlap the second sheet over one-third of the first and press lightly to seal.

On one side of the pastry, leaving a 3/4-inch (2 cm) border all around for sealing, spread a layer of rice in a rectangle.

Add a layer of spinach of the same size, then place the salmon fillets on top, and finally the hard-boiled eggs cut in half.

Season with salt and pepper.

Preheat the oven to 375°F (190°C).

Brush the 3/4-inch (2 cm) border of the pastry with beaten egg. Fold the pastry over the filling and seal the edges.

Brush the entire koulibiac with more beaten egg, decorate as desired, and chill for 15 minutes.

Bake for 30 minutes.