Heat 2 tablespoons of butter in a large skillet over medium heat.
Lightly salt and pepper both sides of each fillet.
Once the butter is just melted, add the fillets and cook for about one minute on each side, just until the fish has a little color.
Add the garlic, shallots, seafood stock, white wine. Bring liquid to a boil, then cover and reduce heat to low.
Poach the fish for 8-10 minutes until the fish is opaque and slightly flaky, but not dry.
Remove fish and set aside on a plate to rest.
Add the peas and tomatoes to the skillet and return the heat to medium-high. Bring to a low boil, add lemon juice, and cook until the peas and tomatoes are slightly soft, about 5-7 minutes.
Plate the fish, then gently spoon peas and tomatoes broth over each fish.
Garnish with parsley and squeeze additional lemon juice over each fillet, as desired.
Add salt and pepper as needed.