Add olive oil to medium sauce pan. Add all vegetables and saute for 5 minutes or until golden; set aside.
Clean fish and season with salt and pepper to taste. Place fish on individual sheets of aluminum foil. Cut lemon so that the juice is extracted easily. Squeeze lemon onto each individual piece of fish to your liking. Add fresh basil and 1 pad of butter to each piece of fish. Then top with vegetables.
Wrap each piece of fish and refrigerate for 1 hour.