1 can condensed milk
1/2 c. lemon juice
3 egg yolks
1 pie crust or graham cracker crust
Cool Whip or meringue

Put condensed milk in bowl. Add egg yolks one at a time, then add lemon juice. Mix well. Place in crust. Top with Cool Whip and place in refrigerator several hours before serving. Meringue is optional; if used brown in oven before refrigerating.