1. In a large bowl, mix 2 cups of flour, 1 tsp. salt, 1/2 tsp. sugar, and 1/2 cup cold butter.
2. Rub with your fingers until it looks like coarse crumbs.
3. Add 5–6 tbsps cold water, one spoon at a time, until it comes together.
4. Shape into a ball, wrap in plastic, and chill for 30 minutes.
5. Heat a splash of olive oil in a large pan.
6. Toss in 1 chopped onion with a little salt and pepper, and cook until soft.
7. Add chopped mushrooms, Parma ham, and a few sprigs of rosemary.
8. Cook 4–5 minutes, then remove from the heat and let it cool.
9. Roll out half the dough into a circle to fit your pie plate.
10. Line the tin with it. Spoon in the cooled filling, then pour over 3 beaten eggs.
11. Roll out the remaining dough for the top crust.
12. Lay it over the filling and seal the edges.
13. Use leftover dough to decorate hearts, if you like. Brush with egg wash.
14. Pop it in a preheated oven at 180°C/350°F for 25–30 minutes, or until golden brown.
15. Serve warm, straight from the oven, with a simple side salad or steamed veggies.

Notes:

• Use Parma ham for a rich flavor, but cooked ham works too.
• Don’t skip cooling the filling before adding eggs; it prevents soggy pie.
• Pie crust can be made a day ahead.