Prepare ½ recipe Quick Puff Pastry. In medium or large mixing bowl, mix together lemon juice, lemon zest, and sugar.
One at a time, peel each apple. Cut each peeled apple in half. Remove core and extra peel.
Cut each half in half again, and then cut into slices approx. ½ inch thick.
Stir apple slices into lemon and sugar mixture. Let sit 30 minutes to 1 hour.
Put butter in frying pan.
Place colander in or over frying pan.
Scrap apples and juices into colander. The mixture will exude about ½ cup of liquid.
Place apples back in mixing bowl.
Heat liquid and butter in frying pan over medium heat, stirring often, until butter is melted and liquid is bubbling.
Continue cooking, stiring often, until liquid carmelizes, turning a light amber.
Remove frying pan from heat.
Add apples, heaping them in the middle.
Preheat oven to 425° F.
Return frying pan to stove and cover.
Cook over medium head for 10 minutes.
Uncover and continue cooking over high heat, basking constantly, until juices cook down and bubble thickly.
Remove from heat.
Roll puff pastry into circle slightly larger than frying pan.
Place pastry on top of apples. Tuck in edges and cut 6 ventilation slits.
Bake approx. 30 minutes, until pastry is golden brown.
Let cool, then serve directly from pan.