Best French Onion Soup

When done caramelizing… Add red wine all at once. Cook until onions are dryer and wine is cooked out.
Remove bay leaves. Sprinkle flour on top and stir – cook 5 minutes until brown. NOW… Pour broth into big stock pot with onions. ADD Balsamic Vinegar. Simmer until a little thicker about 20 minutes and season more with salt and pepper if needed.
Put soup in oven safe bowls, Top with sliced French bread and cover with grated Gruyerre Cheese. Broil on LOW for a few minutes…. Watch continuously until brown and bubbly. Soooooo GOOD!!!