For cream cheese pastry, process butter and flour in a food processor until the mixture resembles breadcrumbs. Add cream cheese and process until a dough forms. Cover with plastic wrap and refrigerate to rest (30 minutes). Preheat oven to 180C. Roll out to 7mm thick, then cut out 12 rounds with a 14cm-diameter pastry cutter. Line twelve 12cm-diameter 300ml pie tins and refrigerate to rest (30 minutes). Trim edges, blind-bake until golden (15 minutes), remove baking paper and weights and bake until golden (5-8 minutes).

Combine shallots, 60ml oil and 1 tbsp thyme in a bowl, season to taste, then scatter in an oven tray lined with baking paper and roast, shaking occasionally, until golden and tender (20-25 minutes). Set aside. Cook potato in a saucepan of boiling salted water until tender (15-20 minutes), drain well and set aside to cool.

Heat remaining oil in a large frying pan over medium heat. Add onion, leek and garlic, and cook until tender (15-20 minutes). Add shallots and remaining thyme, stir to combine, season to taste and combine with potato. Add nutmeg and three-quarters of the Gruyère and season to taste.

Whisk eggs, cream, mustard and chives in a bowl to combine, season to taste and set aside.

Divide potato mixture among pie crusts, top with cream mixture, scatter with remaining Gruyère and bake until golden and set (20-25 minutes). Cool slightly, then remove from tins and serve warm with green salad.