Preheat oven to 350 degrees Fahrenheit. Lightly grease two baking sheets. Spread mushrooms and zucchini pieces on the first baking sheet and chickpeas on the second. Bake one hour, until mushrooms and zucchini are cooked through and chickpeas are crisp and crunchy.

In a colander or sieve, rinse lentils until the water runs clear. Transfer to a bowl. Stir in zucchini, mushrooms, chickpeas and apple.

In a container, shake the mustard, vinegar, oil, salt, and pepper until well combined. Pour dressing over the salad.