In a large saute pan fitted with a lid, pour the olive oil in the pan and heat on medium-high heat. Then add the frozen pearl onions and the water. Sprinkle the sugar on top of the onions. Stir, place lid on top of saute pan, and reduce heat to medium-low. Cook for 15 minutes until onions begin to caramelize (stir every few minutes as needed).
Once the onions are golden and caramelized move the onions to the edge of the pan. Place the green beans in the center and season with salt and pepper (I use about ¼ teaspoon salt and a pinch of black pepper). Place the lid on the pan and cook for 10 minutes (stirring often and add a little water in the pan if needed). Once the green beans are cooked, divide evenly among plates and enjoy.