Hazelnut, shallot and mustard tarts

Method

1. Preheat the oven to 220°C/fan200°C/gas 7. Cut 4 x 15cm rounds from the shortcrust pastry, then line 4 x 9cm tart tins. Line each with baking paper and baking beans, then blind-bake for 10 minutes. Remove the paper and beans. Bake for 4 minutes more. 
2. Heat the olive oil and butter in a pan, then fry the shallots for 4 minutes until soft.
3. Whisk the yogurt with the mustard and eggs. Season well. Divide the yogurt mix among the cases, top with the shallots, then scatter over the hazelnuts. Bake for 12 minutes until set.