When the water for the stock boils, we add a pinch of salt and the defrosted shrimp, then simmer for 3 minutes. We drain the cooked shrimp in the sink in a clean colander and cool 2 minutes under cold running water. We pull the tails off the shrimp and add to our food processor. We count that we have 30 shrimp. We keep 22 in the food processor and the remaining 8 go right into the fridge – covered in a small bowl. The shrimp in the food processor, we pulse to mince. We put the ground shrimp in the fridge in a covered bowl while we get the rest of the soup ready.
We set up a double boiler – we have a large glass bowl above a pot half filled with water. When the water comes to a boil, we add the butter and onion and a pinch of salt to the large bowl. We cook about 8 minutes, the butter melts and the onion softens. We heat the milk in a large measuring cup in the microwave for a minute and add to the butter and onion along with the ground shrimp. We cook, stirring with a flat whisk, for a few minutes. We want the mixture hot but not boiling. We slowly stir in the cream and cook, covered with a piece of foil for just a few minutes to heat. We keep checking and stirring to see when the bisque is hot enough. We taste for salt and add freshly ground white pepper and a squeeze of lemon.
We divide the shrimp bisque in 4 shallow soup bowls. We re-heat the refrigerated shrimp for 10 seconds in the microwave and use them to garnish the soup along with the chives, which are snipped with scissors. We sprinkle on a little paprika and finish the dish with a lemon slice.