Preheat the oven to 400 degrees F. Line a baking sheet with parchment paper.
In a medium bowl, toss together fennel, pancetta, garlic, brown sugar, olive oil, salt, and pepper. Place the ingredients on the baking sheet in a single layer. Cook until the pancetta is crisp and the fennel is caramelized, about 20 minutes. Remove from the oven and let cool for 5 minutes.
In a large bowl, place the salad greens, crumbled pancetta, and caramelized fennel. Toss the salad with the Red Wine Vinaigrette and serve immediately.
Red Wine Vinaigrette:
Mix the vinegar, lemon juice, honey, salt, and pepper in a blender. With the machine running gradually blend in the oil. Season the vinaigrette, to taste, with more salt and pepper, if desired.