In a large salad bowl place mesclun and fruit. Toss lightly to combine.
For dressing, in a screw-top jar combine oil, vinegar, herbs, sugar, garlic, mustard, and pepper. Cover and shake well. Pour dressing over salad; toss lightly to coat.
Divide evenly among salad plates. Sprinkle each serving with nuts and cheese.
Preheat oven to 325 degrees F. Line a baking sheet with foil; butter the foil. Set baking sheet aside.
Spread pecan halves into a shallow baking pan. Bake for 10 minutes, stirring once.
Meanwhile, heat sugar in a medium heavy skillet over medium-high heat, shaking skillet occasionally to heat sugar evenly. Do not stir. Heat until some of the sugar melts (it should look syrupy); begin to stir only the melted sugar to keep it from overbrowning. Stir in remaining sugar as it melts. Reduce heat to medium-low; continue to cook until all the sugar is melted and golden, about 5 minutes. Add butter to melted sugar in skillet, stirring until butter melts and mixture is combined. Remove from heat. Stir in vanilla. Add warm nuts to skillet, stirring to coat. Pour nut mixture onto the prepared baking sheet. Cool completely. Break apart.