- Wash hands with warm, soapy water for 20 seconds. 
- Preheat oven to 450°F.  
- Divide fish fillets into 4 portions and place on 4 sheets of aluminum foil (12x18-inches each). Sprinkle with salt and pepper.   
- Lay lemon rounds over fillets or sprinkle fish with lemon juice.  
- Evenly divide chopped vegetables between packets, placing on top of fillets.   
- Wrap each packet by bringing up the sides. Double fold the top and ends to seal. Leave room for heat to circulate.   
- To bake in the oven, place packets on a baking sheet. Bake at 450°F for 20-30 minutes. Halfway through baking, use a fork to poke small holes in the packet for steam to escape.  To bake in an electric skillet, heat skillet to 400°F. Use a cooking rack in the bottom of the skillet. Pour ½ inch of water into the skillet. Place the packets on the rack. Cover and close the steam vent. If you do not have a rack, make your own with aluminum foil. Form foil into a long snake about 1 inch thick. Form into a coil to fit in the skillet. Place the packets on top of the coil.   
- Packets are done when the fish reaches 145°F on the food thermometer. When cooking is done, carefully open packets to allow steam to escape.