Heat the oven to 375 degrees F. Mix the 1 cup of the biscuit baking mix and the milk until a soft dough forms. Gently smooth the dough into a ball on a floured cloth-covered surface after kneading the ball 5 times to mix. Roll out the dough until it is 2 inches larger than an inverted 9-inch pie pan. Ease into the pan and flute the edges. Set aside. Cook and stir the meat and onion in a large skillet until the meat is brown. Drain off the excess fat. Stir in the salt, pepper, 2 Tb of the baking mix, and the Worcestershire sauce. Turn the meat filling into the pastry lined pie pan. Arrange the tomato slices on the meat mixture. Beat the eggs slightly and stir in the cheese. Spoon onto the tomatoes spreading the mixture to cover the top completely. Bake for about 30 minutes. Cut into wedges and serve with chili sauce, if desired.