Take meat and trim away the fat, then place the meat on a rack in a shallow roasting pan. Take a meat thermometer and place it in the center of the meat. Roast the meat uncovered for 10 minutes in a 425 degree F oven.
While the meat is cooking, mix together preserves or marmalade and mustard in a small bowl. Take half of the mustard mixture and spoon it over the meat and set the remaining mustard mixture to the side.
Roast the meat for an additional 15 to 25 minutes or until the meat thermometer reads 155 degrees F. Take the meat and transfer it from rack to a warm platter and cover with foil. Let the meat stand for 10 minutes before you begin slicing. (While the meat is standing the meat temperature will rise 5 degrees )
While the meat is standing take nonstick coating and spray a medium saucepan. Take mushrooms and green onions and add them to the saucepan. Cook and stir the mushrooms and green onions for about 2 to 3 minutes or until the mushrooms are tender. Take the remaining mustard mixture and orange juice and stir it into the vegetables. Cook and stir the vegetables until they are heated through.
When ready to serve cut the meat into thin slices and spoon the mushroom mixture over the meat.