Prepare crepes.
Combine milk, eggs and salt in small mixing bowl; beat slightly.
Add flour; beat until smooth.
Cover and refrigerate 1 hour.
Lightly butter a 6-inch frypan.
Pour 2 Tbs of crepe batter into pan; rotate pan quickly to spread evenly.
Cook until lightly browned.
Turn; brown lightly on second side and turn out.
Keep warm.
Prepare filling.
Cook contents of rice and seasoning packets according to package directions.
Cook ground beef until crumbly; drain.
Add cooked rice and mushrooms; mix well.
Fill each crepe with 1/2 cup rice mixture; roll up.
Place on large heatproof platter or 13 1/2 x 8 1/2-inch baking dish.
Prepare sauce.
Melt butter or margarine; stir in flour, then soup and milk.
Cook until thickened, stirring constantly.
Stir in remaining rice mixture.
Pour over filled crepes.
Sprinkle with cheese.
Bake at 350°F oven untilv cheese is melted, 15 to 20 minutes