Solving this helps save time on busy weeknights while keeping traditional flavors. To make a quick kulebyaka using supermarket ingredients, buy ready-made puff pastry sheets. Lay down the first sheet on a baking tray. Add a base layer of cooked white rice to absorb moisture. Follow this with a layer of sautéed mushrooms, chopped hard-boiled eggs, and flaked canned salmon or cooked chicken. Place the second puff pastry sheet on top, crimp the edges firmly to seal, and bake at 200°C for 25 minutes until golden brown.