Fish En Papillote

Bahan-bahan (4 porsi)

• 4 6 -ounce cod fillets (or another firm-bodied fish, such as salmon,flounder, trout, or halibut)
• 1/4 cup softened butter (or butter spread with canola oil)
• 2 g arlic cloves (minced)
• 2 tablespoons chopped fresh parsley (plus additional for serving)
• 1 small or 1/2 large shallot (diced)
• ½ teaspoon kosher salt (plus additional for seasoning)
• ¼ teaspoon ground black pepper
• 1 small lemon
• 4 cups lightly packed tender salad greens (like spinach, arugula, radicchio, or even mixed greens)
• 12 cherry tomatoes (halved)