Slowly fry sliced onions in a little butter, some olive oil and thyme. The slower you cook the onions the nicer these tarts will be - I cooked mine for a good 40-50mins.
While the onions are cooking roll out and cut some pastry to size for the dish / dishes that you are using - blind bake them for 10/15 mins if you wish.
Beat enough eggs to fill your tarts and combine with some sour cream or creme fresh and season with salt & pepper.
Finaly assemble the tart by adding the cooked onion, crumbling in a cheese of your choice and filling with the egg mixture and bake in a pre-heated oven til cooked.
I used three different cheeses for the tarts pictured - one is with Morbier, one Comte and the last one a good french goats cheese.
I also made a beetroot and goats cheese tart with some left over pastry & onion mixture. Just add some balsamic vinegar to the onion and boil a beetroot - slice and arrange on top of the onion with some goats cheese and bake (no egg mixture on this one).
If you are feeling really ambitious assemble the beetroot in the dish first put the onion mixture on top of that - then top with the pastry tucking into the sides of the dish, bake and turn out for a beetroot tarte tatin.
