Melt butter in saucepan over medium-high. Add onions and saute until soft.
Stir in flour and cook to make a roux. Don't let butter get beyond light gold. It does not need to brown.
Stir in chicken stock a little at a time. Adjust throughout cooking to get the consistency that you like. Cook down, while stirring, at least 10 minutes.
Toss in the parsley, thyme and bay leaves.
Salt and pepper to taste. Maybe salt a little more.
Simmer and stir for at least 10-15 minutes. More is better.
Remove bay leaves and stems and pour into bowls.
Top each bowl with a slice of French bread and 2-3 slices of cheese.
Place bowl in 450 degree oven for just a few minutes until cheese is getting brown. Serve immediately.