Heat 3 tbsp of olive oil in a large skillet over medium heat.

Add the diced onion and sauté until softened and translucent, about 5 minutes.

Stir in the rice and cook for 2-3 minutes, until the rice is well coated with oil.

Add 1 ½ cups of water and the salt to the skillet. Stir well, then cover and let the rice simmer on low heat for about 10 minutes or until the water is absorbed and the rice is partially cooked.

Lay out a vine leaf on a clean surface, with the smooth side down and the stem end facing you.

Place about 1 tablespoon of the rice filling in the center of the leaf, near the stem end.

Fold the sides of the leaf over the filling, then roll it up slightly tight from the stem end, tucking in the sides as you go. Repeat with the remaining leaves and filling.

Line the bottom of a large pot with vine leaves to prevent sticking.

Arrange the dolmades seam-side down in the pot, packing them closely together in a single layer.

Drizzle olive oil and pour a cup of water into the pot, place lemon slices, and then cover the dolmades with a heatproof plate to keep them from unrolling during cooking.

Cover the pot with a lid and cook over low heat for about 45-50 minutes, or until the rice is fully cooked and the leaves are tender.

Allow the dolmades to cool slightly before serving. They can be enjoyed warm or at room temperature, drizzled with additional lemon juice if desired.