1. Beat egg whites until very stiff. 2. Gradually beat in Sugar; continue beating until glossy. 3. Add lemon juice. 4. Reserve 3 tbsp. of mixture; into the remainder, fold ground hazelnuts. 5. Drop heaping tsp. on prepared baking sheet. 6. Put a small dab of reserved mixture on each and press in a hazelnut in the middle. 7. Bake at 325 degrees for 20 minutes.