Heat 1 1/2 tsp butter, oil, thyme, and caraway in a skillet. (I used a cast iron). Once butter is melted add brussels sprouts. Cook 6-7 minutes until browned.
Remove from pan and set aside. Use the rest of the butter and add garlic and onions. Saute until tender. Add Brussels Sprouts back in and stir in syrup, vinegar, mustard. Salt and pepper to taste.