Preparation Sauté pancetta in nonstick skillet over medium heat until crisp, about 6 minutes. Drain on paper towels. Pour drippings in skillet into bowl. Add shallots, vinegar, mustard and thyme; whisk to blend. Add oil; whisk to blend. Season with salt and pepper. (Can be made 1 day ahead. Cover and chill. Bring to room temperature before continuing.) Combine spinach, pears, red onion and pancetta in large bowl. Toss with enough dressing to coat. Surround salad with radicchio leaves and serve.
Preparation Sauté pancetta in nonstick skillet over medium heat until crisp, about 6 minutes. Drain on paper towels. Pour drippings in skillet into bowl. Add shallots, vinegar, mustard and thyme; whisk to blend. Add oil; whisk to blend. Season with salt and pepper. (Can be made 1 day ahead. Cover and chill. Bring to room temperature before continuing.) Combine spinach, pears, red onion and pancetta in large bowl. Toss with enough dressing to coat. Surround salad with radicchio leaves and serve.