Melt butter and one tablespoon of oil in a saucepan and soften shallots and garlic.
Toss lamb and kidneys in a bowl with flour, chopped rosemary, salt, and pepper.
Brown the meat in the pan in batches over high heat.
Return all meat and shallots to the pan and de-glaze with red wine.
Add stock, simmer for five minutes, season, and let the filling cool completely.
Generously butter a 1.2 litre pudding basin.
Mix pastry ingredients with approximately 225ml of water to form a soft dough.
Roll out three quarters of the dough to a 30cm circle and line the basin.
Fill the basin with cooled meat, roll out the remaining dough, and seal the lid.
Cover with pleated parchment and foil and secure tightly with string.
Steam the basin in a covered pan of boiling water for 2 to 2.5 hours.
Rest for five minutes, invert onto a plate, and serve.