In a small bowl, stir 4 Tbs. of the vinegar and 1 tsp. of the sugar until the sugar dissolves. add the shallot, let sit for 15 minutes, and then drain.
Meanwhile, in a large bowl, whisk the remaining 2 Tbs. vinegar, 2 Tbs. oil, the remaining 1-1/2 tsp. sugar, the fish sauce, and 1/4 tsp. salt. Set aside. Combine the curry powder and 1/2 tsp. salt in a small bowl and sprinkle evenly over both sides of the shrimp.
Heat the remaining 1 Tbs. oil in a 12-inch nonstick skillet over medium-high heat. add the shrimp and cook, flipping once, until just opaque, 2 to 3 minutes total.
Add the shallot, mâche, apple, and cashews to the bowl with the vinaigrette, and toss to coat. Top with the shrimp, and serve immediately.
nutrition information (per serving):
370, Fat Calories
21, Saturated Fat
2.5, Polyunsaturated Fat
5, Monounsaturated Fat
Photo: Scott Phillips