£4, 4 portions: Bean Pot Pie

Ingredients

• 1 tbsp olive oil
• 1 ⁠onion
• 1 clove garlic ( or 1 tsp garlic granules)
• 2 ⁠carrots
• 3 stalks celery
• 300 g puff pastry
• 400 g butter beans (tin)
• 300 g frozen peas
• 400 ml stock
• 1 tbsp flour
• ⁠salt and pepper
• ⁠milk (to brush the pastry)