Saute carrots and onions with olive oil, until golden brown. Take 1/4 of the sauted mixture and set it a side.
Combine the rest of it with cooked rice, season and set it a side.
Defrosted cabbage, remove leaves from cabbage head.
Cut out the hard part of the lettuce leaves.
Place the lettuce leaf in your hand, add filling.
Fold over lettuce into a roll.
Push the top of the pocket into the filling.
Place the rolls really tight, right next to each other, in a baking dish (ceramic dish or iron dutch oven). Cover the top of the cabbage rolls with sauted onions and carrots (once you set a side).
Bake at 350F, 30-45 minutes.