First, peel the onions and cut them in half and then into slices.
In a large pot or dutch oven, sauté the onions with a drizzle of olive oil over medium-high heat. After they start to become translucide, add the butter and sauté for another 10 minutes until golden brown.
Deglaze with the white wine and cognac and stir with a wooden spoon to loosen the brown bits that have clung to the bottom of the pot. Let reduce for 2 minutes.
Add the flour and mix well. Pour in the vegetable broth and season with pepper and nutmeg. Simmer on medium heat for 30 minutes.
Cut the slices of baguette and toast them. Count one or two slices per serving. Rub the toasted baguette slices with a fresh garlic clove.
Place your mini casseroles or oven-proof bowls or ramekins on a baking sheet covered with parchment paper. Pour a ladle of soup into each mini casserole.
Place one or two slices of baguette on top. Top with grated cheese. Broil in the oven for 3-5 minutes.
Serve while still warm.
