1 tablespoon olive oil
2 pounds yellow sweet onions, sliced thin
1 tbsp unsalted butter
2 tbsp flour
1 bay leaf
1 sprig dried thyme
1/4 cup dry sherry
1/4 cup dry white or red wine
8 cups beef stock (2 1/2 containers) (low sodium is best)
kosher salt and freshly ground pepper, to taste
- 1/2 cup freshly grated Parmesan cheese
- 1/4 cup freshly grated Asiago cheese
In a Dutch oven, or large pot, sauté the onions with the butter and olive oil over low heat, until the onions are soft and golden, about 30 minutes. Increase the heat to medium and cook until the onions begin to caramelize, about 20-25 minutes, stirring every few minutes. Add the sherry and wine and reduce the heat to low, stirring the brown bits that get stuck to the pot. Simmer until the liquid cooks down and evaporates, 2-3 minutes. Add the flour and cook, stirring for 3-4 minutes. Add the stock, thyme, and bay leaf, increase heat to high, and bring to a boil. Cover and simmer gently for about 20 minutes. Remove bay leaf and thyme and season with black pepper to taste.
For the cheese crisps:
Preheat the oven to 400 degrees. Line a baking sheet with parchment paper. In a small bowl, combine the Parmesan and Asiago. Put 2 tbsp of the cheese mixture onto the baking sheet and lightly pat it with your fingers into a 4-inch round. Repeat with all the cheese. Bake until golden and crisp, 6-8 minutes. When ready to serve, ladle soup into an oven proof safe bowl and place a cheese crisp on top. Place bowl on cooking sheet and broil for 3 minutes. Serve immediately.
Note*- If you do not have an oven safe soup bowl, feel free to microwave your soup with the cheese crips on top.