Preheat oven to 350°. Peel the onions and cut each one in half. Then cut each half into thin half moons. Heat 2 Tbsp olive oil in a skillet over medium high heat. Add in your onion slices and cook down for 5 minutes, stirring occasionally. Next, add in 1-2 Tbsp brown sugar to help caramelize the onions. Continue cooking on low for 25 minutes, stirring occasionally until caramelized. Set aside in a bowl.