Preheat oven to 400 degrees F.
Combine zucchini, squash, salt, pepper, Italian seasoning and 2 tbsp olive oil in a medium bowl.
Lay out four 14-inch-long sheets of parchment paper on a work surface. Divide the zucchini/squash among the four parchment papers and place into the center. Put the halibut fillets on top of the bed of zucchini/squash. Brush the fillets with olive oil, season with salt and pepper, and give each fillet a squeeze of a lemon wedge.
Fold the parchment over the fish, then fold the edges over in small pleats to seal the parchment packet. Transfer all four packets to a large baking sheet. Bake for 20 minutes until veggies are tender and fish is cooked through.
While the fish is cooking, combine all of the relish ingredients in a small bowl and set aside.
Once fish is done, snip the parchment open with scissors, serve the fish with martini relish and additional lemon wedges.