In a skilled, pour in some oil and cook the onions slowly. Just before they turn brown, add the green bell pepper, celery, water chestnuts and garlic. As they get soft, turn up the heat and add the mushrooms and cook for a few minutes.
Turn down the heat and add pepper, thyme, paprika, dry mustard and celery salt. Cook for a few more minutes and add sugar, Tabasco, soy sauce, Worcestershire sauce, and lemon juice. Stir in and heat for a minute.
Let sit for about 15 minutes and then mix into the meat. Place in a casserole. Cook in a 350 degree F oven for about 1-1 1/2 hours until done. If you split it into two smaller casserole dishes, baking time is 30-45 minutes.
Strain off any grease and cut into serving pieces. Serve with mashed potatoes and taco sauce or catsup.