1. For Tart- Rub the cold butter with the flour and salt till it resembles coarse crumbs (some may also be pea-size crumbs).
2. Add ice-cold water.  Using your fingers, mix very gently to bring the flour and butter mixture together to form a dough (do not work too much on the dough).
3. Wrap the dough in a cling film and refrigerate it for 30 mins.
4. Take out the dough, place it between two parchment papers and roll it gently to form a circle of 14 inches diameter.
5. Grease the tart pan.
6. Very gently place the rolled crust in the tart pan (9 inches) uniformly and cut out the extra portion.
7. Pre-heat oven at 375 degrees Fahrenheit.
   
8. Now fill the tart generously with pie weight, kidney beans or raw rice.
   
9. Bake the tart crust for 15 minutes.
   
10. Once done, allow it to cool for a few minutes and very carefully remove the    pie weight.
    
11. For Quiche- Heat olive oil in a pan.
    
12. Add fish fillet, season it with salt and pepper.  Lightly sear it until just          done. Take it off the heat, cool it and shred it into chunks.
    
13. In a bowl, add eggs, cheesy garlic mayo, Italian seasonings, orange zest,      salt and pepper. Beat it to mix them well.
    
14. Now, take the tart and layer it evenly with the cooked fish chunks.
    
15. Evenly, sprinkle spring onions over the fish layer.
    
16. Gently add the prepared egg and mayo mixture over the fish layer.
    
17. Bake the quiche in a preheated oven at 350 degrees Fahrenheit for 35 to      40 minutes or until the quiche is done and a toothpick comes out clean. 
    
18. Let the quiche rest in the oven for a few more minutes.  Once it cools down    a  bit, cut into pies and serve warm.

Enjoy your meal!