- 14 ounces [400 g] onions [peeled under water to avoid crying]
- 4 tablespoons [60 g] butter
- 1 tablespoon [8.75 g] flour
- Freshly grated nutmeg
- Salt and pepper, to taste
- 6 cups [1.5 L] boiling chicken or beef broth [if you lack courage, use cubes]
- 1 egg yolk
- 1 cup [250 mL] Port wine
- Heavy cream
- Bread slices [a little dry is ok]
- 5 1/4 ounces [150 g] grated Gruyere cheese [at home, it's less expensive and tastier]
- Salt and pepper [freshly ground 5-grain is always best]
- Chop then brown onions into melted butter.
- Stir in flour; cook for a few minutes more.
- Mix in a little grated nutmeg; salt and pepper.
- Pour in boiling broth and leave to simmer for approximately 20 minutes.
- For an even tastier soup, prepare soup up to this point in the morning and let soup sit until ready to reheat at the end of the day.
- Preheat oven to 400°F [200°C].
- Mix together egg yolk, Port wine and a little cream into a bowl.
- Into an oven-safe dish, arrange slices of bread sprinkled with grated Gruyere cheese before pouring in soup.
- Stir in egg yolk mixture.
- Transfer into a hot preheated oven, for 30 minutes.
- If desired, broil soup for a few minutes before serving.