What is Estonian sprat sandwich?

Question

TasteAtlas · Accepted Answer

This traditional Estonian open-faced sandwich consists of a slice of rye bread that is topped with a marinated sprat fillet. The bread is often buttered, or coated with munavoi—the coarse egg and butter spread—while the fillets are occasionally complemented by poached or hard-boiled eggs, green onions, and fresh herbs. This nutritious sandwich is commonly found at local restaurants and is often served on festive occasions.