Bananas don’t keep a particularly nice colour when cooked but when mixed with feijoas the perfume is exotic and the sweet-sharp taste is intense.
75g (2½ oz) standard flour 120g (4 oz) butter, softened and cut into small pieces 3 Tbsp caster (superfine granulated) sugar 75g (2½ oz) rolled oats 50g (about 12 nuts) Brazil nuts, sliced 3 Tbsp shredded or desiccated coconut Pinch of ground cinnamon Finely grated zest 1 lemon 800g (1½ pounds) or more, feijoas 1 Tbsp lemon juice 1-2 frozen bananas, briefly thawed (or nicely ripe banana)
1 Preheat oven to 180°C (350°F). Sift the flour into a bowl and rub in butter with the fingertips (or use two knives or a pastry blender) until well amalgamated. Mix in sugar, oats, nuts, coconut, cinnamon and lemon zest.
2 Halve feijoas and scoop out flesh. Put feijoa flesh in a bowl and sprinkle with lemon juice, then toss lightly. If using frozen banana, thaw briefly, split skin and scoop out pulp. If using mature fruit, peel and slice thickly. Mix with feijoas.
3 Pile fruit into a lightly buttered ovenproof dish. Spoon crumble on the top, mounding it nice and high as it will sink as it cooks. Bake for about 30 minutes, until fruit is bubbling around the sides of the dish and the crumble is nicely browned.
Don’t press hard on the crumble, just pat gently into place to avoid knocking out air and making the crumble hard. Once the crumble is nicely browned, drape a piece of tin foil over the top to stop the nuts burning.