Step 1

Preheat oven to 350 degrees. Heat oil in a large, heavy ovenproof saucepan over medium heat. Cook onion until edges start to caramelize, 10 to 12 minutes. Add sugar, and cook 1 minute more. Add vinegar. Scrape up brown bits from bottom of pan with a wooden spoon. Stir in cider, stock, cinnamon, bay leaf, 1 1/2 teaspoons salt, and 1/4 teaspoon pepper. Add cabbage, arranging in a single layer. Bring to a boil. Cover; transfer to oven. Braise until cabbage is tender, 40 to 45 minutes.

Step 2

Transfer cabbage to a serving platter using a slotted spoon; discard cinnamon stick and bay leaf. Bring remaining liquid in saucepan to a simmer over medium-high heat. Cook until reduced by half, about 10 minutes (you will have about 1 cup sauce). Spoon sauce over cabbage.