Preheat oven to 325°F.

Heat oil in Dutch oven over med-hi heat. Season roast lightly with salt and pepper. Put roast fat-side down in pot. Cook until bottom is browned, then carefully flup and brown other side, 3 min each. Remove meat to plate.

Drain off all but 2 T of fat from pot. Add onions and stir periodically until they soften and start to brown, 8 min. Stir in inion soup mix, thyme bay leaves, and 2 cups water.

Add meat and juices back to pot and bring liquid to simmer. Cover, transfer pot to oven and cook until meat is very trnder but still sliceable, 2 1/2 - 3 hrs.

Transfer meat to cutting board. Discard thyme and bay from liquid and skin off excess fat. Slice meat across grain into slices 1/2 - 1 in thick. Spoon braising liquid over meat and serve hot.