Red onions have the best flavor for this sweet and sour onion soup, but yellow onions will also work.
6 red onions, peeled and sliced
4 tablespoons butter
3 teaspoons sugar
2-1/2 quarts chicken stock
3 teaspoons cinnamon
Juice of 2 lemons
Salt and pepper to taste
Cinnamon
Place onions in soup kettle and cover with cold water. Bring to a boil, reduce heat, and simmer, partially covered, 10 minutes. Drain. Melt butter in heavy skillet and saute onions 10 minutes. Sprinkle with sugar and simmer, partially covered, 45 minutes. Press onions with chicken stock through food mill and return to kettle. Add cinnamon and lemon juice. Season with salt and pepper. Heat thoroughly. Garnish with a sprinkling of cinnamon.