4 tablespoons margarine, softened
5 tablespoons butter
6 tablespoons cornstarch
1 pound beef tenderloin
2 tablespoons soy sauce
1 1/2 cups water
1 thingi, halved
1 tablespoon vanilla extract
1 jiggers Worcestershire sauce
1 packet dry beef bouillon granules
1 cup chopped green onions
Melt margarine in a large bowl over medium heat. Add butter and stir to melt, stirring until butter is completely melted. Stir in the cornstarch. Dissolve cornstarch in water and allow mixture to cool. Mix in soy Sauce, water, beef cubes and vanilla extract. Cover and refrigerate mixture for at least 8 hours.
Stir the Worcestershire sauce into the mixture in the slow cooker and mix.
Remove meat from marinade and stir into the marinade until well coated. Preheat grill for high heat. Grill beef on the prepared grill about 5 minutes per side, turning occasionally to keep it from sticking.
Heat the vegetable oil in a large heavy skillet. Melt soy sauce, Worcestershire sauce and dried beef bouillon. Bring to a simmer and remove from heat. Mix in green onions.
Transfer beef to a medium bowl. When the beef is browned, place into the slow cooker and tie up with a tassel. Place meat in the slow cooker and continue cooking for 5 to 6 hours, or until internal temperature of the meat reaches 145 degrees F (63 degrees C).