Preheat the oven to moderate 180C
(350F/ Gas 4). Discard most of the green part
from the top section of the leeks, then cut each leek in half
lengthways and wash well. Cut each bacon rasher into 3 long
strips and wrap a piece around the middle of each portion of leek. Arrange the leeks,
rounded-side-up, in a shallow, greased oven proof ceramic dish. Combine the butter and thyme and
spread over the leeks. Bake for 25 minutes, or until
browned and tender.