Combine ground beef and onion in a large skillet.
Cook over medium heat until beef browns,
stirring to crumble beef; drain.
Stir in tomatoes, tomato paste, thyme,
and 3/4 tsp salt; bring to a boil.
Cover, reduce heat, and
simmer 30 minutes, stirring often.
Cook macaroni according to package directions,
adding 1/4 tsp salt; drain.
Stir in Feta cheese and egg whites.
Add to beef mixture; stir well.
Spoon mixture into a lightly greased
13- x 9- x 2-inch baking dish.
Melt butter in a heavy saucepan over low heat;
add flour and cinnamon, stirring until smooth.
Cook 1 minute, stirring constantly.
Gradually add milk; cook over medium heat,
stirring constantly, until mixture is thickened and bubbly.
Stir in remaining 3/4 tsp salt.
Gradually stir about one-fourth of
hot mixture into egg yolks;
add to remaining hot mixture, stirring constantly.
Cook 1 minute, stirring constantly.
Pour sauce over beef mixture;
bake at 350F for 35 to 40 minutes.
Remove from oven;
let stand 10 minutes before serving.
Sprinkle with paprika.
Yield: 8 servings.