Prepare the onions up to 2 days ahead and refrigerate. Add them to the green beans in a last-minute sauté just before serving. The onions are thawed to reduce the liquid that can splatter in the hot pan.
2 tablespoons olive oil, divided
2 (16-ounce) packages frozen pearl onions, thawed
1 tablespoon sugar
1 teaspoon salt, divided
2 pounds green beans, trimmed
1/2 teaspoon black pepper
How to Make It
Heat 1 tablespoon oil in a large nonstick skillet over medium heat. Pat onions dry with paper towels; add to pan. Increase heat to medium-high; sauté onions 5 minutes. Add sugar and 1/2 teaspoon salt; sauté 15 minutes or until onions are tender and golden brown. Spoon into a bowl.
Heat 1 tablespoon oil in pan over medium-high heat. Add beans; sauté 8 minutes or until crisp-tender. Add onions, 1/2 teaspoon salt, and pepper; cook 2 minutes or until mixture is thoroughly heated.