Butternut Squash Chana Masala (Trust me, I'm Indian!)

Ingredients

• 2-4 tbsp oil
• 1 tsp mustard seeds
• 1 tsp cumin seeds
• 1 onion (diced)
• 11-12 curry leaves
• 5-7 garlic cloves (grated)
• 2 tsp grated ginger
• 4 cups cubed butternut squash
• 1 tbsp coriander cumin powder (or half of each)
• 2-3 tsp kashmiri chili powder
• 1/2 tsp turmeric powder
• salt (to taste)
• 1 tbsp tomato puree
• 3/4 cup tinned chopped tomatoes
• 2 x 400g tinned chickpeas (drained and rinsed)
• 1 cup water (plus more if needed)
• 1 1/2 tsp brown sugar
• 1-2 tsp lemon juice
• 1/8 tsp ground cinnamon
• 3-5 tbsp coriander leaves