Add flour, salt, sugar and butter cubes into a wide bowl. Using your fingertips break all the butter cubes and rub it with flour. Add chilled water little at a time and knead.
Transfer the flour mixture on the work surface and knead to make a smooth dough.
Roll the dough and cover it with cling wrap and place it in fridge for about 1 hour.
Homemade Pastry -
For simple homemade pasty add flour, salt, sugar and butter cubes into a wide bowl. Using your fingertips break all the butter cubes and rub it with flour. You flour should have crumbled texture. Add chilled water little at a time and start to knead.
Transfer the flour mixture on the work surface and knead to make a smooth dough. This will take a few minutes. Be gentle while kneading. You don't want to over work it.
Roll the dough and cover it with cling wrap and place it in fridge for about 1 hour. Meanwhile lets make caramelized onions.
Caramelized Onions –
Heat butter in a wide pan. Add thin sliced onions into the pan and sweat the onions. Once onions are wilted and begin to brown add salt and sugar, cook until onions are nice softened and browned evenly. Add balsamic vinegar, lime juice and thyme; increase heat to high; boil for 2-3 minutes to reduce, stirring occasionally. Take off the heat and set aside to cool.
Prepare Tart -
Preheat the oven to 400 F and line a sheet pan with parchment paper. Remove pastry from fridge and allow it to come to room temperature for 10 minutes. Then divide into 2 equal portions. Roll each portion into thin sheet of about 2mm thick. Place the dough on the prepared sheet pan and trim the edges. Refrigerate again for 10 minutes. Fill a parchment sheet with uncooked beans. Place it over the prepared tart. Pop this into an own and bake for about 7 minutes or until you see brown spots on the tart. Remove the uncooked beans parchment filling.
Whisk ricotta cheese into smooth mix. Spread a layer of it over the tart and fill it with caramelized onions over the top, sprinkle some more salt and pepper powder over the top and sprinkle some thyme leaves. Bake in own for about 15 minutes more. Cut and serve warm.