Devien shrimp. Rinse the shrimp in cold water and set aside.
Bring 6 cups of water with salt to a boil in a medium sauce pan over high heat.
Cut the carrot into large pieces. No need to peel it. Cut the celery into large pieces. Peel and quarter the onion. Quarter a lemon. Rinse 3-4 sprigs of parsley.
Add the carrot, celery, 1/4 onion, 1/4 lemon and 3-4 sprigs of parsley to the water.
Once the water comes to a boil, add the shrimp. Leave the heat on high.
Allow the water to come back to a boil. When the shrimp begin to rise to the top, they are cooked.
Turn off the heat and drain the shrimp over the sink into a colander.
Place in a bath of ice water to stop the cooking. Or just spread them on a serving dish and let them cool in one layer.