For a number of years now, variations of this onion tart have become part of my "crowd-pleasing, fool-proof and good for what-ails-ya" collection of recipes  because of the colours, simplicity and intense flavours. Vegetarians could easily omit the anchovies and this tart would be equally delicious. A few steps are required from you before you can start devouring the tart but all of them are easy.  You can eat this hot or cold, on a plate or not, dress it up or down, it's all up to you. All in all it will likely take you three to four hours from start to completion and most of it will be waiting time. You can make more than one tart at a time as the recipe can be easily doubled. This tart will serve 6 (hungry) people.

Caramelised Onion Tart with Tomatoes

Ingredients for tart dough:

Plain flour: 300 grams

Icing sugar: 1.5 teaspoons

Salt: 3/4 teaspoon

Unsalted butter: 200 grams, cold and cut into 1 cm cubes

Egg yolk: 1 large or 1.5 medium or 2 small

Lemon juice: 1.5 teaspoons

Iced water: 2.5 tablespoons

Parmesan cheese: 6 heaped tablespoons, grated

Preparation:

Place flour, sugar and salt into a large bowl. Add butter and using a pastry blender, blend butter into the flour mixture until it forms pea-sized bits first and then continue until mixture resembles coarse breadcrumbs. You can do this with your fingertips but make sure you have cold fingers (dip them in icy water for a few seconds) as you don't want the butter to melt into the flour.

In a small bowl beat egg yolk along with iced water and lemon juice.

Unify egg yolk mixture with flour mixture using a fork. Once 3/4 of the mixture starts holding together use your hands to press the pastry into one piece.

Shape it into a flat disk, about 2 cms thick, wrap in plastic and refrigerate for 2 hours (or more, even overnight). Do not be tempted to omit this step, relaxing the dough in the fridge is crucial if you want to minimise shrinking in the oven.

In the meantime prepare tart topping, see below for ingredients and method.

Once the topping has been prepared you should be able to remove pastry dough from the fridge. Leave the pastry out of the fridge for 20 minutes before rolling, it will otherwise be rock solid and too difficult to work with.

Lightly dust a work surface with plain flour, and working from the centre outwards and rolling in one direction only form a rectangle 25 cm x 37 cm. That's the size of the largest tray that will fit into my oven comfortably. You should play with different sizes and shapes according to your equipment and oven, just remember to adjust cooking times accordingly. Ensure the edges of the rolled pastry are slightly raised, this is to ensure the topping doesn't spill out of the tart and into your oven...I quite dislike cleaning my oven when that happens.

Sprinkle dough with Parmesan cheese.

Ingredients for caramelised onions and tomato topping:

Good quality extra virgin olive oil: 3 tablespoons or to taste

Red onions: 2 kilos, sliced into 5mm slivers

Aged balsamic vinegar: 4 tablespoons

Brown sugar: 5 teaspoons

Salted or brined anchovies: 8, turned into a paste using mortar & pestle along with the garlic and chilli

Garlic: 4 cloves, roughly chopped

Fresh hot chilli or chilli flakes: 1/2 or to taste, chopped finely or 1/2 teaspoon flakes

Ripe Roma tomatoes: 5, sliced

Fresh basil: 1 medium bunch, leaves only

Salt and pepper

Heat olive oil in a medium sized pot on high heat, add onions and stir continuously until they become translucent, about 5 minutes. Lower heat to medium, add vinegar and sugar  and continue cooking for another 5 minutes. Add anchovy, chilli and garlic paste and 1/2 bunch of basil and lower heat to simmer. Cook for 1 hour while stirring sporadically. Taste onions and add salt and pepper to taste. Let it cool. Preheat oven to 190C.

Spread onion mixture on rolled out pastry, place tomatoes on top,  sprinkle some salt and pepper on them, drizzle with a bit of olive oil and bake for about 45 minutes or until pastry is cooked throughout and edges are light golden brown. Depending on your oven, this might take up to an hour.

Drizzle with some more oil, scatter basil leaves on top and serve hot or at room temperature.