HOW TO MAKE FRENCH ONION SOUP?
(1)Melt butter in a stockpot over medium-high heat.
(2)Add onions and cook, stirring occasionally, until tender and brown.
(3 ) Add beef broth, white wine, vinegar, thyme, salt, and pepper, bring to a simmer.
(4)Combine the chicken broth with the flour and then add to the onion mixture. 10 minutes.
(5)Line a baking sheet with tin foil and place the baguette slices down flat. Place into oven and broil for 1-2 minutes per side, until golden.