1-First, preheat your oven to 425 degrees Fahrenheit and position a rack in the center to get things started right. This step sets the stage for even cooking and helps lock in those fresh flavors.

2-Next, in a small bowl, combine the 1/4 cup butter or butter spread mixed with canola oil, 2 minced garlic cloves, 2 tablespoons chopped fresh parsley, 1 small or half large shallot, 1/2 teaspoon kosher salt, and 1/4 teaspoon ground black pepper. Add the zest from 1 small lemon and mash until smooth for a flavorful base. Now, tear four squares of parchment paper, each at least 12 inches wide, and place 1 cup of salad greens in the center of each square, leaving space at the top and bottom.

3-Lay one 6-ounce fish fillet on top of the greens vertically and lightly season with kosher salt. Spread one-quarter of the butter mixture over each fillet, then top with 2 thin lemon slices and scatter 6 halved cherry tomatoes around each for added zest and color. Fold the sides of the parchment up and roll to seal tightly, then roll and crimp the top and bottom edges, tucking the ends underneath to keep everything inside.

4-Place the packets on a rimmed baking sheet and bake for 12 to 15 minutes, until the fish is cooked through and flakes easily. Once done, serve warm with the reserved lemon slices and extra parsley to brighten up the plate. This method not only makes for a simple fish en papillote recipe but also ensures your meal stays moist and full of taste.