Using the potato peeler peel and quarter apples. Remove the core.
In a sauté pan on medium high heat melt butter and sugar. Add the lemon juice, salt and vanilla. Then add the apples. Cook for 15-20 minutes or until the sauce reduces by half.
Preheat the oven to 375°F or gas mark 5. Roll out the puff pastry to make circle 11 inches in diameter.
If using 2 pans grease the second pan liberally. Take a fork to move the apple quarters from one pan to the next and arrange with the outer edge of the apples touching the pan. Working from the outside in overlap the apples until all fit. Cover with the puff pastry and tuck the edges down the side of the pan.
Bake for 45 minutes or until the crust is golden brown.
Allow to cool for at 45 minutes this will allow he sauce the cool and thicken. Cover with a plate or platter and invert the pan toe release the tarte Tatin. If any apples stick place them back on the tarte.