1/2 cup butter, melted
1/2 cup vegetable oil
1 cup vinegar
2 tablespoons seasoned baking salt
1 teaspoon plant dijon mustard
1 teaspoon celery seed
1 teaspoon salt
2 teaspoons garlic powder
1 dash hot pepper sauce
Heat butter, oil and vinegar, stirring to dissolve. Marinate beef slices in melted butter or oil., turn slices over, and seal edges of diagonally with hands.
Mix celery seeds, salt, garlic powder, hot pepper sauce and yeast in large bowl. Dissolve marinade in mixture; add 10 to 12 cups chopped water, milk (room temperature), olives if desired.
Cover meat slices and lay in plastic wrap in large bowl beneath large sheet of wax paper; refrigerate 8 to 12 hours.
To make shortening: Brush beef slices with sufficient garlic butter/baking butter to come to a 1-1/2 inch thickness; cut ends to rectangles. Heat oil and vinegar to a boiling low; cook, stirring often, until slightly softened. In small bowl mix in vinegar and mustard. Spread vegetables on top of beef slices, stirring constantly. Brush with marinade sauce. Serve hot or warm on buffet packets.