-
1
Combine all lemon-tarragon mayo ingredients in a food processor until smooth and green.
-
2
Cover with plastic wrap and refrigerate until ready to use.
-
3
Fill the largest pot you have 2/3 of the way full with water, then add several teaspoons of salt and bring to a boil.
-
4
Meanwhile, fill a large bowl with ice and water.
-
5
While you're waiting for the water to boil, pulse the shrimp, 1/4 pound of butter and lemon zest in a food processor until it's a a chunky paste.
-
6
Working one at a time if necessary, drop the lobsters into the boiling water, lower the heat slightly and cook for two minutes.
-
7
Remove lobsters from the pot, transfer to the ice bath and wait 5 minutes until completely cool.
-
8
Using claw crackers, remove all the meat from the shell and chop it into roughly 1 1/2-inch pieces.
-
9
Reserve any tomalley or other innards for another use.
-
10
In a mixing bowl, gently combine the butter and the meat of both lobsters and season lightly with sea salt.
-
11
Divide the mixture between two buttered metal ring molds on a plate, pack in firmly and refrigerate for an hour.
-
12
Run a sharp knife around the inside of the ring molds to release the patties, then wrap each patty around the circumference with aluminum foil (which will help it hold together while cooking) and tie loosely with butcher's twine or other sturdy string.
-
13
Refrigerate for another half-hour or until very firm.
-
14
Remove burgers from the fridge and dust each side lightly with 00 flour.
-
15
Heat the 2 tablespoons of butter in a large cast-iron skillet over medium heat until hot and foamy, then carefully place the foil-wrapped burgers in and sear on one side for 3-4 minutes until golden-brown.
-
16
Flip to the other side and transfer to the oven for 10 minutes.
-
17
Remove burgers to plates and allow to rest for 5 minutes, then snip off foil and twine and transfer burgers to buns.
-
18
Top with lemon-tarragon mayo and butter lettuce leaves and serve.
