Preparation - Spray a shallow 2 quart microwave-safe casserole or baking dish with non-stick cooking spray. Place the sliced apples in the prepared casserole. Sprinkle with lemon juice. Microwave on full power for about 4 minutes or until the apples are tender-crisp, stopping to stir once or twice during the cooking time. In a small bowl, mix the oats, flour, cinnamon, nutmeg, and salt together. Sprinkle the mixture over the cooked apples. Microwave on full power for 4 to 6 minutes or until the apples are tender and the topping is bubbly. Serves 4 to 6.