In a large skillet heat 1 tablespoon of olive oil and ½ tablespoon sesame oil in it over medium high heat.
Add the onions to the skillet, and saute for 3-5 minutes until they begin to soften.
While the onions cook, combine all of the ingredients for the hoisin sauce in a small mixing bowl and whisk to combine.
Mix the 2 pounds of ground meat into the skillet with the onions, and cook until fully browned.
Add the hoisin sauce into the skillet with the meat mixture.
Add the water chestnuts to the skillet with the cooked ground meat.
Pour in 2 tablespoon of soy sauce, ½ tablespoon rice wine vinegar, 1 teaspoon minced garlic, 1 tablespoon chili garlic sauce, 1 teaspoon ginger paste and salt and pepper to taste. Stir to combine completely.
Enjoy with butter or bibb lettuce!