Preheat the oven to 400 degrees F. Have 4 sheets of parchment paper ready to go. Season the cod all over with salt and pepper. As a note, if your asparagus spears are thick, I suggest cutting them in half lengthwise since we're only roasting for 15 minutes.
Cook the orzo in salted water according to the package directions. This most likely calls for boiling it for 8 to 10 minutes. Drain the orzo and drizzle it with the olive oil. Toss with the fresh lemon zest and the ½ cup chopped herbs.
While the orzo cooks, make the garlic butter. Heat the butter in a saucepan over low heat until it melts. Stir in the garlic. Remove from the heat.
Make the parchment paper packet. I use a rectangular sheet of parchment that is 8x12 inches. I fold up short sides. I place ½ cup of the orzo in the center. I add in a few asparagus spears, cherry tomatoes and green onions (all divided evenly between 4 packets). I usually spray the vegetables with some olive oil spray and then season with salt and pepper. Place the cod filet on top.
Drizzle the fish and vegetables with some of the garlic butter - 1 tablespoon or a little more. Place a lemon slice or 2 on top. Fold up the long edges over the fish until they touch, then fold them down together to one side, continuing to tighten and roll the packet until it’s sealed.
Place all the packets on a sheet pan. Roast for 15 to 18 minutes, or until the fish is easily flaked with a fork.
Remove from the oven and serve the packets. If you have extra garlic butter leftover, drizzle it on and serve!