In a bowl, combine the bulgur and boiling water. Set aside for 15 minutes or until the bulgur has softened. With a large spoon, transfer the bulgur to a large fine-meshed strainer set over a bowl. Drain, pressing out excess liquid with the back of the spoon. Wipe out the first bowl and return the bulgur to it. With a fork, fluff the grain and leave to cool to room temperature.
In a large skillet over medium heat, heat 2 Tbsp. of the olive oil. Add the scallions and cook for 1 minute. Add the summer squash, zucchini, salt and pepper. Cook, stirring occasionally, for 3 minutes more. Stir in the mushrooms. Set aside to cool.
Add the zucchini mixture, chick peas, tomatoes, mint, parsley, remaining 2 Tbsp. olive oil and lemon juice to the bulgur. Taste for seasoning and add more salt, pepper or lemon juice if desired.