In a bowl, mix together the soy sauce, vinegar, brown sugar, oyster sauce, and sesame oil.
Heat the vegetable oil in a large skillet over high heat and add the chicken in a single layer.
Sprinkle with a little salt, then leave it alone to brown.
Once browning, stir to brown all sides.
Add garlic and ginger.
Add peppers, cooking for 3 mins.
and stir to combine. Stir in the bell pepper and let it cook for 2 to 3 minutes.
Pour in the sherry and scrape bottom of pan.
On medium low, add the sauce.
Mix the cornstarch/water and pour it in.
Add chestnuts, corn and cashews.
If sauce is thick add a little bit of water to thin it at this point.
Garnish with scallions and toasted sesame seeds