Turkey and Sugar Snap Peas with Orange-Mustard Sauce

Here is a particularly high-spirited dish, infused with the perfume of sweet oranges and French Dijon mustard.

Ingredients: 
Sauce
1/2 cup fresh orange juice
1 tsp finely chopped orange zest
1 Tbs soy sauce
1 tsp finely chopped, peeled fresh ginger
1 clove garlic, minced
1 shallot, finely chopped
2 tsp honey
1 tsp Dijon mustard

Marinade
1 egg white
1 Tbs mirin or sake
2 tsp soy sauce
1 Tbs cornstarch

1 lb boneless, skinless turkey breast meat, cut into 1 1/2 chunks (or tofu for a vegetarian version)
2 Tbs peanut or vegetable oil
1/4 lb sugar snap peas or snow peas
1 cup canned water chestnuts, rinsed, well drained and sliced

To make the sauce, combine the orange juice and zest, soy sauce, ginger, garlic, shallot, honey and mustard in a small bowl and stir to mix well. Set aside.
To make marinade, combine the egg white, mirin or sake, soy sauce and cornstarch and stir to dissolve the cornstarch. Add the turkey pieces and toss to coat evenly. Set aside.
In a wok or frying pan over high heat, warm 1 Tbs of the oil, swirling to coat the bottom and sides of the pan. When the oil is very hot but not quite smoking, add the peas and stir and toss every 15-20 seconds until just tender, 2-3 minutes. Add the water chestnuts and stir and toss for a minute longer. Transfer to a dish and set aside.
Reduce the heat to medium-high. Add the remaining 1 Tbs oil to the pan, again swirling to coat the pan. When oil is hot, add turkey pieces and stir and toss every 15-20 seconds until firm and no trace of pink remains, 4-5 minutes. Be sure to distribute the turkey evenly in the pan so it comes into maximum contact with the heat and cooks evenly.
Quickly stir the reserved sauce and add to the pan over medium-high heat. Bring to a simmer and stir and toss until the sauce thickens slightly, 1-2 minutes. Return the peas and water chestnuts to the pan and toss to coat with sauce. Cook for 1 minute longer.
Taste and adjust the seasonings. Serve immediately.