Sprinkle tenderloin with garlic salt and pepper.
Insert meat thermometer into tenderloin, making sure it does not touch fat.
Grill over medium coals 15 minutes on each side or until thermometer registers 140° (rare), 160° (medium), or 170° (well done).
Set aside, and keep warm.
Prepare rice according to package directions.
Set aside, and keep warm.
Place bouillon in a medium saucepan, and bring to a boil.
Reduce heat, and simmer bouillon, uncovered, while completing recipe.
Combine sherry and cognac in a small, long-handled saucepan; heat just until warm (do not boil).
Remove from heat.
Immediately ignite sherry mixture with a long match, and pour over bouillon.
When flames die down, stir in butter, dijon mustard, tomato paste, worcestershire sauce, 1/2 teaspoon garlic powder, and vinegar.
Cook, uncovered, over low heat 15 minutes.
Stir in mushrooms and green onions; cook an additional 5 minutes.
Remove sauce from heat.
Cut tenderloin into 1/2 inch slices.
Place rice on a serving platter; top with meat and sauce.