Ukrainian Holubtsi with Mushroom and Buckwheat Filling

Carefully remove the core from the cabbage head. Place the cabbage in a large pot of boiling water and cook for 10-15 minutes, or until the outer leaves are tender enough to peel off easily. Remove leaves as they soften, trimming the thick rib from each. Set aside.

Rinse the buckwheat groats thoroughly. In a small saucepan, combine 1 cup buckwheat with 2 cups water. Bring to a boil, then reduce heat to low, cover, and simmer for 15 minutes, or until water is absorbed. Fluff with a fork and set aside.

Heat 1 tablespoon of olive oil in a large skillet over medium heat. Add the chopped onion and cook for 5-7 minutes, until softened and translucent. Add the chopped mushrooms and cook for another 8-10 minutes, until their liquid has evaporated and they are lightly browned.

Stir in the minced garlic, dried dill, 1/2 teaspoon salt, and 1/4 teaspoon black pepper into the mushroom mixture. Cook for 1 minute more until fragrant. Remove from heat and combine with the cooked buckwheat in a large bowl.

To assemble the holubtsi, place about 2-3 tablespoons of the buckwheat-mushroom filling near the stem end of each cabbage leaf. Fold in the sides of the leaf, then roll tightly from the stem end to form a compact roll.

In a large Dutch oven or oven-safe pot, spread a thin layer of crushed tomatoes on the bottom. Arrange the cabbage rolls snugly in layers over the tomatoes. Pour the remaining crushed tomatoes and vegetable broth over the rolls.

Cover the pot and bake in a preheated oven at 350°F (175°C) for 1 hour and 30 minutes, or until the cabbage is very tender and the sauce is bubbly. Check halfway through and add a little more broth or water if the sauce seems too thick.

Carefully remove the holubtsi from the oven. Let them rest for 10 minutes before serving to allow the flavors to meld and the rolls to firm up slightly.