Recipe(tried): Chateaubriand steak

Approx. 4 lbs. sirloin or scotch fillet (i.e. a large, very tender piece of
beef)
Marinade:
1 cup oil
4 tbsp. soy sauce
2 cloves crushed garlic
2 tsp. celery salt
4 tbsp. lemon juice
4 tbsp. chopped green onion
2 tsp. coarsely ground black pepper
Remove any small pieces of surface fat from the steak. Wipe well with damp
paper towels. In a shallow baking dish make marinade by combining the above
ingreds. Place meat in marinade for at least six hours in the fridge and then
bring to room temperature.
Bake at 400 degrees for 20 min. each side on grilling rack, basting frequently
with marinade. Cut into meat to see if done to your liking (we like this VERY
rare.)
Take out of oven and let rest for 1 to 2 hours.
Reheat in oven before serving. Serve with Chasseur sauce.
Chasseur sauce:
4 tbsp. oil
1 cup hot beef stock
Freshly ground black pepper
1 cup white wine
1/2 chopped fresh mushrooms
2 tbsp. flour
1-2 tsp. salt
1/2 tsp. basil
3 tsp. tomato paste
Heat oil in pan, stir in flour and continue stirring until mixture becomes
light brown. Add beef stock, basil and wine. Stir in tomato paste, add
mushrooms and cook, stirring constantly, until mixture thickens.