Trim and finely chop the leek, chop the carrots, and peel and finely chop the garlic. Chop the almonds, plus a few extra to serve, then toast until golden. Pick the dill, then cube the feta.
Heat the oil in a pan over a low-medium heat, and sauté the leek and carrots for a few minutes. Add the garlic, cumin seeds and a splash of water, season, then cover and gently cook until the veg is soft, about 5 minutes. Stir often, adding water if it catches.
Blanch the cabbage leaves in boiling salted water for 2 to 3 minutes, drain and lay out on a board. Fold most of the almonds, the dill and feta into the veg mix, then spoon 3 tablespoons into the centre of each leaf.
Roll up and place, seam-side down, in a baking dish. Drizzle with oil, cover and bake for 15 minutes. Serve with a the reserved almonds on top.