Beat the egg whites until foamy, using an electric mixer at medium speed.
Add the lemon juice and continue beating until stiff.
Gradually add the sugar, beating continuously.
When all of the sugar has been added, continue beating 7 to 8 minutes longer (on high speed), or until very stiff.
Remove 1/2 cup of the meringue for icing; then fold the nuts into the remainder.
Drop by teaspoonfuls onto a well-greased cookie sheet, spacing them 2 inches apart.
Make a small depression with a teaspoon on the top of each meringue.
Then drop a bit of icing into the depression and press a hazel nut into the center.
Bake in a 275° oven for about 25 minutes, or until firm.
Cool the macaroons on the sheet.
To remove, drop the sheet on a table or counter (the cookies will spring off).