Ratatouille Sub

Ingredients

• 1 long, thin aubergine, such as a Japanese variety
• 1 long, thin courgette
• 1 long, thin yellow squash
• 1 to 2 red peppers, long and narrow if you can find them
• 1/2 small yellow onion
• 250g tomato puree or tinned tomato sauce
• 1 garlic clove, finely chopped
• 2 tbsp olive oil
• salt
• chilli flakes or piment d'Espelette
• 1 tbsp chopped fresh herbs, such as thyme
• 2 20cm sub rolls, or the equivalent length of baguette