• In a large kettle cook the onions in the butter over moderate heat, stirring frequently, for 40 minutes, or until they are golden brown.
• Sprinkle the onions with the flour and sugar and cook the mixture, stirring, for 3 minutes.
• Add the broth slowly, stir the soup constantly until it comes to a boil, and simmer it, covered, for 20 minutes.
• Season the soup with salt and pepper.
• Put 2 slices of the toast in each of 6 heated soup bowls, top each toast with 1 tablespoon of the Gruyère, and pour the soup over the toasts.

POULET SAUTE’ AUX HERBES DE PROVENCE
Chicken:
1/2 cup (1 stick) butter
1 3 to 3 1/2-pound chicken, cut into 8 pieces, rinsed, patted dry
1 teaspoon dried thyme or savory
1 teaspoon dried basil
1/4 teaspoon fennel seeds, ground in spice mill or with mortar and pestle
3 unpeeled garlic cloves
2/3 cup dry white wine or 1/2 cup dry white vermouth

Sauce:
2 large egg yolks
1 tablespoon fresh lemon juice
1 tablespoon dry white wine or dry white vermouth
2 to 3 tablespoons butter, cut into 1-inch cubes (optional)
2 tablespoons chopped fresh basil, fresh fennel fronds, or fresh parsley (optional)

For chicken: 

• Melt butter in large wide pot over medium-high heat.
• Working in batches, if necessary, add chicken pieces and cook only until golden, turning occasionally, about 8 minutes per batch.
• Transfer chicken breast pieces to plate.
• Sprinkle remaining chicken pieces in pot with half each of thyme, basil, and fennel seeds, then salt and pepper.
• Add garlic to pot.
• Cover pot; reduce heat to medium and cook 8 to 9 minutes.
• Sprinkle chicken breasts with remaining thyme, basil, and fennel seeds, then salt and pepper.
• Return breast pieces to pot; baste chicken with butter in pot.
• Cover and cook until chicken is cooked through, turning and basting occasionally, about 15 minutes.
• Transfer to hot platter; cover.
• Remove peel from garlic cloves; mash garlic with spoon or fork in same pot.
• Add 2/3 cup wine to juices in pot; boil until liquid is reduced to 3/4 cup, occasionally scraping bottom of pan, about 8 minutes.
• Pour reduced pan juices into measuring cup and reserve for sauce.

For sauce: 

• Off heat, whisk egg yolks in heavy small saucepan until beginning to thicken.
• Whisk in lemon juice and 1 tablespoon wine.
• Gradually whisk reserved pan juices into eggs, 1 teaspoon at a time.
• Set sauce over very low heat and whisk constantly until warm and slightly thickened, 3 to 4 minutes.
• If desired, whisk in butter, 1 piece at a time.
• Remove from heat.
• Stir in herbs, if desired.
• Season sauce to taste with salt and pepper.
• Spoon sauce over chicken and serve.