French Onion Soup is one of those dishes I order every time I see it on a menu but rarely make at home. I’m not sure “what preventeth me” (as Dad says); the hardest part is cutting up the onions (and for me, the patience to let them caramelize). But I’ve always believed the key to the best French Onion Soup is rich, homemade stock and in the past, if I didn’t have that, I wouldn’t even think about making it.
But a few weeks back when Andy and I were with Mom and Dad in Pennsylvania for the weekend we were majorly craving this soup. We had all the ingredients, but lacked the all-important homemade stock. Necessity is the mother of invention, so Mom and I used vegetable stock to make the soup and amped up the flavor by stirring in some miso paste at the end.
We made enough to have it for a couple nights which was a culinary blessing. I was nearing the end of my pregnancy and still working full time. There was nothing more satisfying on a frigid winter evening than a bowl of ready-to-eat French Onion Soup topped with crunchy French bread and melted cheese waiting at home.
- 2 tablespoons each: butter and olive oil, plus extra oil for brushing bread
- 4 large sweet onions (about 2½ pounds), halved and sliced thin
- 1 quart chicken broth
- 2 tablespoons flour
- ¼ cup sweet vermouth
- 18½-inch slices cut from a baguette
- 6 slices Swiss or Provolone cheese, about 4 ounces
- 6 tablespoons grated Parmesan cheese
- Heat butter and oil in a soup kettle over high heat. Add onions: cook, stirring often, until dramatically reduced and light caramel brown, 10 to 15 minutes. Reduce heat to medium; continue to cook onions, stirring frequently until rich caramel 10 to 15 minutes longer.
- Meanwhile, microwave broth in a 2-quart Pyrex measuring cup until piping hot, about 5 minutes.
- When onions are fully cooked, stir in flour, and then vermouth, and finally hot broth. Bring to a boil, reduce heat to low and then simmer, partially covered to blend flavors, about 5 minutes. Whisk in water as necessary to achieve lightly thickened soup.
- When ready to serve, adjust oven rack to middle position and turn on broiler. Lightly brush both sides of bread with oil and broil, turning once, until golden brown on both sides.
- Place 4 soup bowls (diameter should be only slightly larger than cheese slice) on a sturdy baking rimmed baking sheet. Ladle hot soup into bowls; top with croutons, cheese slice, and then grated Parmesan. Broil until cheese is melted and spotty brown, 2 to 3 minutes.