Pie Filling:

1. Start by frying the onions and garlic in a little olive oil, then add the red bell pepper and cook for a few minutes just until it starts to soften but still firm.

2. Remove from heat and allow to cool. 

3. Add in the thawed spinach, remaining ingredients and mix well together. Set aside. 

Shortcrust Pastry:

1. Sift the flour into the bowl of a stand mixer or food processor.  

2. Add the cubed butter and mix or pulse until the mixture resembles fine crumbs.  Gradually add cold water until the dough forms. 

3. Tip the dough onto a surface and gently bring it together with your hands, then shape it into a disc. Wrap in clingfilm and chill for 30 minutes.  

Pie Assemble:

1. Preheat oven 180C/350F.

2. Generously butter grease a 28cm pie dish. 

3. Roll out half of the pastry and place into your prepared pie dish. Spoon in filling and level the surface. Close the pie with remaining pastry. 

4. Brush the top with egg wash and bake on the bottom shelf of the oven for about 60-90 minutes, until pastry is cooked and golden. 

5. Remove from oven and let it rest for 10 minutes before serving.

6. Enjoy!