1 kg cooking apples (usually Bramleys or Granny Smiths work well)
160g flour (e.g. Untreated Baker's n.4)
40g jumbo oats (e.g. Flahavan's Organic)
120g chilled unsalted butter
160g caster sugar
zest of half a lemon
1 tbsp lemon juice
Chop the butter into cubes. Add together with flour and oats in a bowl and rub it all together to a texture like rough bread crumbs.
Add half of the sugar (80g) and mix together. Leave in the fridge (covered) while you assmble the rest of the ingredients.
Preheat your oven to 180C/gas mark 4/350F
Peel the apples, core them, and cut into chunks. Toss the chunks with lemon zest and juice, add the rest of the sugar (80g) and water. Tip into a shallow oven baking dish.
Take topping out of the fridge and scatter on top, forming a few little chunks as you scatter across the top. Bake for around 40 minutes until the topping starts to turn golden and filling bubbles a little at the edges.
Optionally, tpo with creme fraiche, whipped cream, or even ice cream or custard for sweet tooths!