Fit pie shell into bottom of tart pan and fit into and around edges. Some dough should drape over top edges of pan.
Using a rolling pin, roll across top of pan, trimming edges of dough even with top edge of pan.
Prick the shell with a fork to help prevent shrinking.
Cover edges with a strip of foil to help prevent burning.
Bake on center rack of oven for 10 minutes, then remove foil and continue baking for about 5 minutes or until golden brown. Remove to wire rack to cool.
In a 2-quart saucepan, using a wire whisk, beat eggs and egg yolks until combined.
Stir in lemon juice and sugar.
Cook over medium heat, stirring constantly until mixture thickens and coats the back of a spoon. (approx. 15 minutes)
Stir in butter until melted.
Pour filling into shell and refrigerate for at least 4 hours or overnight.
Cover edges of tart with a foil strip to prevent overbrowning. Sprinkle 3 tablespoons of granulated sugar across top of lemon filling.
Place the tart under broiler, closest to heat source. Broil for several minutes, until sugar melts and browns. Watch carefully so sugar does not brown too much.
Remove tart from broiler and chill for about 1 hour.
Remove sides of tart pan by pushing up from the bottom and put on a plate.
Warm apricot preserves in microwave or on stovetop just until melted.
Brush top of tart with the preserves.
Place 3 large egg whites in mixing bowl. (saved from egg yolks used in filling.) Beat on high speed while slowly adding ¼ cup granulated sugar and ¼ tsp. cream of tartar. Continue beating until mixture thickens and forms stiff peaks.
Pipe border of tart with the meringue, using a #1M open star tip.
Place tart under broiler to brown meringue or use a bakers torch to brown it.