Bring 4 quarts water and salt to a boil in a large Dutch oven. Plunge lobsters, head first, into boiling water; return to a boil. Cover, reduce heat, and simmer 10 minutes; drain and cool.
Break off large claws and legs. Crack claw and leg shells using a seafood or nut cracker; remove meat and set aside.
Break off tails. Remove stomachs and intestinal veins.
Cut shell of tail segments lengthwise on the underside. Pry open the tail segments; remove meat, and cut into1/2-inch slices. Chill lobster meat.
Combine minced shallots and next 7 ingredients in a jar; cover jar tightly, and shake vigorously.
Arrange lettuce on individual salad plates; top with lobster, and drizzle with shallot mixture. Garnish, if desired.