In a 10- to 12-inch frying pan, arrange frozen potstickers in a single layer. Add 2/3 cup water and salad oil. Cover and bring to a boil over high heat, then reduce heat and simmer until liquid cooks away and potstickers begin to brown, 12 to 17 minutes. (Or cook as package directs.)
Cut red peppers into thin strips.
In a large bowl, mix hoisin, lemon juice, toasted sesame oil, sugar, ginger, and garlic.
Add salad mix to bowl and mix with dressing.
Spoon salad onto dinner plates and top with equal portions of red peppers and hot potstickers.