To make shortcrust pastry, put the flour and butter in the bowl of a food processor and process until mixture resembles breadcrumbs. With motor running, add egg yolk and enough water to form mixture into a ball.
Turn dough out onto a lightly floured surface and knead until just smooth. Roll out until 3mm thick. Put 6 small (10cm x 2cm) quiche tins on top of pastry as a guide and cut pastry to fit. (You can also use 12cm tins to make 8 quiches.) Remove bases from tins. Line tins with pastry and trim edges. Press pastry into fluted sides so it finishes slightly above the edge. Gather, knead and reroll scraps. Repeat to line another 6 quiche tins. Freeze pastry cases for at least 20 minutes.
Tip: Baking quiches in tins with the bases removed allows the pastry to brown and crisp on the bottom, without blind baking.
To make filling, preheat oven to 190°C. Heat oil in a large non-stick frying pan over a medium heat. Add kale and garlic and cook, stirring, for 2 minutes or until just wilted. Allow to cool. Sprinkle cheese into pastry cases. Line 2 oven trays with baking paper. Transfer pastry cases to prepared trays.
Put eggs, cream and milk in a bowl. Season, then whisk until smooth. Spread kale mixture evenly on top of cheese. Top with salmon. Pour egg mixture over salmon in cases.
Bake for 20-25 minutes or until golden and set. Allow to stand for 15 minutes, then transfer from tins to a wire rack. Serve warm or at room temperature.