French Onion Soup Crouton Salad

**Caramelize the Onions:** Heat 2 tablespoons of olive oil in a large skillet over medium-low heat. Add the sliced onions, brown sugar, and thyme. Cook, stirring occasionally, for 20-25 minutes, or until the onions are deeply golden brown and caramelized. Season with salt and pepper.

**Prepare the Croutons:** Preheat the oven to 375°F (190°C). Brush the baguette slices with the remaining 2 tablespoons of olive oil. Grill the baguette slices on a grill pan or grill for 1-2 minutes per side, or until lightly toasted. Top each baguette slice with a spoonful of caramelized onions and sprinkle generously with grated Gruyere cheese.

**Bake the Croutons:** Arrange the croutons on a baking sheet and bake for 5-7 minutes, or until the cheese is melted and bubbly.

**Make the Vinaigrette:** In a small bowl, whisk together the red wine vinegar, balsamic vinegar, Dijon mustard, minced garlic, salt, and pepper.

**Assemble the Salad:** In a large bowl, toss the winter greens mix with the red wine vinaigrette. Divide the salad among four plates. Top each salad with several French onion soup croutons. Serve immediately.