These whole roasted onions are seasoned with sweet balsamic vinegar and fresh thyme. The long roast time leaves them soft and buttery, almost melting in your mouth with each bite.
Slice off the tops of the onions and a small sliver on the bottom so that they sit flat. Leave the skin on around the outside and place in a small 8 inch cast iron skillet.
Drizzle the onions with the olive oil then season with the salt, pepper, balsamic vinegar and thyme. Break the butter up into small pats and place on top of each onion.
Roast for 45 minutes to 1 hour until golden brown and soft.