Makes 6 servings2 leeks, washed thoroughly and diced 3 green onions, minced 2 large sweet onions, diced 2 large red onions, diced 5 Tbsp butter 1/2 tsp sugar 2 Tbsp balsamic vinegar 1 tsp minced fresh rosemary Salt and pepper, to taste 1. Cook leeks, green onions, sweet onions and red onions in butter over medium-high heat until the liquid they give off evaporates, about 10 minutes. 2. Add sugar, vinegar, rosemary, salt and pepper. Cook and stir until onions begin to brown at edges. Serve warm or at room temperature as accompaniment to any roast meat.