Place a large bare metal sheet pan in the oven and heat to 450°F.
Trim the squash and cut into 3/4-inch half-moons. Blot the cut surfaces if visibly wet.
Toss with olive oil, salt, garlic powder and pepper until lightly coated.
Spread on the hot pan in one layer with gaps. Roast 10 minutes without moving.
Flip the pieces, scatter Parmesan evenly, and roast 7 to 12 minutes more until browned at the edges and just tender.
Rest 3 minutes, then add lemon zest and herbs. Serve before the hot squash releases more liquid.