Prepare Cabbage: Bring a large pot of water to a boil and submerge the cabbage, cooking for about 10 minutes until outer leaves are tender. Remove and cool, carefully peeling off leaves.

Make Filling: In a skillet, heat olive oil over medium heat; sauté onions, leeks, and white parts of spring onions until softened, about 5 minutes. Add rice and water to cover, stir in meat, dill, parsley, salt, and pepper until combined.

Form Rolls: Lay a cabbage leaf on a surface, remove tough stem, spoon filling on leaf, fold sides, roll tightly. Arrange rolls seam-side down in pot, packing snugly.

Cooking Setup: Layer leeks, carrot, bay leaves, and celery at pot bottom. Place rolls on top, cover with water or broth, drizzle oil, cover with a plate, simmer over low heat for 1 hour.

Prepare Sauce: Drain cooking liquid into a bowl. In another bowl, whisk eggs, lemon juice, and zest. Slowly add warm liquid to egg mixture while whisking to avoid curdling.

Combine and Serve: Make a roux with flour and remaining stock, stir into egg mixture. Pour sauce back into pot with rolls, gently heat, serve garnished with fresh pepper and lemon zest.