In a large nonstick skillet or wok, stir-fry halibut in 2 teaspoons hot oil for 3-4 minutes or until fish flakes easily with a fork; remove and keep warm.
Add the yellow squash, zucchini, mushrooms, cumin and remaining oil to the pan. Stir-fry for 2-3 minutes or until vegetables are crisp-tender. Add garlic; cook 1 minute longer. Return fish to the pan. Add salsa; heat through. Sprinkle with cilantro.