Slice the squash and zucchini lengthwise in quarters. Cut the lengths in half. (You should end up with pieces 3 to 4 inches long and about the thickness of two pencils.)
Place a large skillet in the oven and preheat to 325°F.
Place the cumin, oregano, cocoa powder, maple syrup, salt and pepper in a bowl and blend together with a rubber spatula. Add the squash and toss well to coat.
Add the olive oil to the hot pan and then the pumpkin seeds and the squash and zucchini.
Roast for 15 minutes. Toss frequently.
When the squash is cooked, place it in the taco shells and top with the shredded cheese and lettuce.
Serve.
