Butter beans with urfa chilli butter

Ingredients

• 50g unsalted butter
• 1 tsp urfa chilli flakes
• 1 preserved lemon, seeds removed, finely chopped (20g)
• 2 tsp lemon juice
• 1 onion, thinly sliced (160g)
• 2 garlic cloves, crushed
• 1 tsp ground cumin
• 1 tbsp double cream
• 700g jar of butter beans, with the liquid, or 2 x 400g tins
• Flaked sea salt