Wash greens, soak in ice water for a few minutes to crisp. Drain and spin dry thoroughly
Wash pear. Cut in half, remove core and seeds. (If you have a nice ripe pear, you should be able to take out the center with your measuring teaspoon.) Cut the pear into chunks. Sprinkle them with lemon juice.
In a small bowl, mix oil, 1 tsp lemon juice, salt and pepper to taste. Add powdered mustard and whisk briskly. Dress the greens. Toss them with the walnut and cheese crumbles. Gently fold in the pear. A large salad for one or a side salad for two.