Step 1. To make the pastry, combine the flour & butter in a food processor. Gradually add a little water as the machine works, until the mixture comes together. Turn out onto a board, mould together into a ball firmly with your hands & wrap in clingfilm. Place in the fridge for at least 20 minutes.
Step 2. Preheat the oven to 200c.
Step 3. When your 20 minutes are up, roll the dough out on a floured surface, and use it to line a greased flan/quiche tin. Line with parchment paper & baking beans, and blind bake for 15 minutes.
Step 4. Remove from the oven, remove the paper & beans, and scatter half of the cheese onto the pastry.
Step 5. Spread the tomatoes and onion evenly over the cheese, then top with the remainder of the cheese.
Step 6. In a bowl, beat the milk and eggs together, add the basil and season well.
Step 7. Pour the mixture over the top and then place in the oven for 30 minutes - until the top is golden brown and slightly firm to the touch, Remove from the oven, allow to rest for around five minutes then turn out of the tin to serve and enjoy.
Step 8. Serve the quiche with a lightly dressed salad, homemade coleslaw, and boiled new potatoes.