Preheat the oven to 325 degrees F. Halve or quarter any large potatoes. In shallow dish large enough to hold potatoes in a single layer, toss potatoes with butter; season with salt and pepper. Spread in single layer. Roast potatoes, uncovered, for 45 minutes, stirring once or twice during roasting.
Meanwhile, in small dish, stir together vinegar, maple syrup, and sliced garlic. Drizzle potatoes with vinegar mixture, gently tossing with a spoon or spatula to coat. Continue to roast about 10 to 20 minutes more, until potatoes are fork-tender and glazed, stirring once or twice.
To serve, sprinkle potatoes with green onions, thyme, and lemon peel. Makes 6 servings.