Most "Indian" restaurants in Britain are actually run by Bangladeshis, & the most revered town for food in Bangladesh is Sylhet. This recipe originates in Sylhet, but interestingly uses bright red kashmiri chilli powder, chilli jam & tomato to give it the bright red colour.
If you wish to make it hotter, just add more chilli powder or Hawkshead Relish Chilli jam.
Garlic (73%), Acetic Acid, Sunflower Oil, Mustard Seeds, Salt, Cayenne Pepper, Turmeric, Red Chilli Peppers.
Allergens in bold