Bring water and brown sugar to a simmer in a large nonstick skillet over medium heat; cook until the sugar is completely dissolved, about 2 minutes. Stir in walnuts; cook, stirring often, until the sugar is golden and caramelized, about 2 minutes. Spread the walnuts evenly on a parchment paper-lined plate. Wipe out the pan.

Step 2

Stir shrimp, honey and 1 tablespoon oil together in a bowl. Return the skillet to medium-high heat. Add the shrimp mixture; cook, stirring occasionally, until the shrimp are well browned and cooked through, about 4 minutes. Remove from heat. Combine mayonnaise, lemon juice, pepper, salt and the remaining 1 tablespoon oil in a small bowl; add to the shrimp mixture in the pan, stirring to coat. Sprinkle with the caramelized walnuts and scallions. If desired, serve with rice.