Preheat the oven to 400 degrees.Tear 4 sheets of parchment, measuring approximately 16 inches in length. Crumple the sheets into a ball, then flatten them back out. This makes the parchment more manageable.Mix the minced garlic and shallot together in a small bowl.In the middle of each sheet, lay 1 cod fillet, 4 asparagus spears and 4 cherry tomatoes. Drizzle each with olive oil. Sprinkle kosher salt over each packet and a spoonful of the garlic/ shallot mixture. Lay slices of lemon over each piece of fish. Gather the two long sides of the parchment together and roll tightly down towards the fish. The corners nearest to the bottom need to be tightly rolled to prevent any of the juices from running out. Place the packets on a sheet pan and place the pan in the preheated oven.Roast for 17 minutes, then carefully unfold the parchment. Sprinkle with fresh chopped parsley and wedges of lemon.