Sprinkle fish with 1/4 teaspoon salt and black pepper.
Heat 1 teaspoon oil in a large nonstick skillet coated with cooking spray over medium-high heat until hot. Add fish; cook 3 minutes on each side or until fish flakes easily when tested with a fork. Remove from skillet; keep warm.
Combine 1/4 teaspoon salt, 2 teaspoons oil, squash, and next 8 ingredients (squash through garlic), and toss well. Wipe skillet with paper towels; recoat with cooking spray. Add vegetable mixture, and sauté 4 minutes or until crisp-tender. Serve fish over vegetables; garnish with basil, if desired.
Other Notes
Substitute any firm, white-fleshed fish for these sautéed bass fillets.