Remove the breasts from the rotisserie chicken. Discard any skin and chop into large chunks. Add chopped chicken (about 2 cups) to the bowl of a food processor along with the frozen greens, 2 chopped scallions, 2 minced cloves of garlic, and 1 egg. Sprinkle in 1 tsp of cornstarch, 1½ tbsp of soy sauce, 1 tbsp of sesame oil, and a pinch of kosher salt and freshly ground black pepper. Pulse the mixture a few times until moist and well combined.