Walnut, Lemon and Cardamom Cake

• 230 g butter
• 230 g caster sugar
• 175 g<

Preheat the oven to 160°C/325°F/Gas 3. Have ready a 25cm spring-form tin lined with greaseproof paper, and place this on a baking sheet.

Beat the butter and sugar together until light and very pale. Stir in the walnuts and almonds, then the eggs, one at a time. Add the polenta,