Heat oil to medium heat. Add pork, garlic and ginger. Season with salt and pepper and brown.
Once meat is cooked, add soy sauce, orange juice, crushed pineapple and water chestnuts. Cook for 5 minutes and set aside (cover with foil to keep warm).
In a small bowl, whisk together sauce ingredients and add to pan.
Bring to a boil and turn down the heat to low until the sauce thickens (about 2 minutes).
Place in iceberg lettuce leaves and layer with rice, meat and sauce.