Ingredients

• 3 tablespoons canola or grapeseed oil
• 1 teaspoon mustard seeds
• 1/2 teaspoon cumin seeds
• 1 medium red onion, finely diced
• 3 cloves garlic, thinly sliced
• 1 (1-inch thumb) ginger, peeled and minced
• 1/2 teaspoon turmeric
• 1/2 teaspoon store-bought or homemade garam masala, recipe follows
• 1/2 teaspoon paprika
• 1/4 cup apple cider vinegar
• 1 (14 1/2-ounce can) diced tomatoes
• 2 tablespoons molasses
• Kosher salt and freshly ground pepper
• 3 large cinnamon sticks (if you have the kind you get at Indian stores, it's about 3 tablespoons of cinnamon bark bits)
• 3 tablespoons whole cloves
• 1/4 cup green cardamom pods, shelled, husks discarded (about 2 tablespoons of seeds)
• 4 large black cardamom pods, shelled, husks discarded (about 1 tablespoon of seeds), optional

Instructions

1. Watch how to make this recipe.
2. Warm the oil in a medium saucepan over medium-high heat until nearly smoking.
3. Keep your lid handy. Add the mustard seeds and the cumin seeds; they should start enthusiastically popping upon contact with the oil, so cover the pot until the spluttering subsides, about 30 seconds.
4. Add the onions and saute until soft and just starting to brown, 5 to 7 minutes. Add the garlic and ginger, and saute until the garlic is soft, about 2 minutes longer.
5. Add the turmeric, garam masala and paprika. Stir and cook about 30 seconds. Then add the vinegar (standing back so you don't inhale the fumes!) and cook 1 minute more.
6. Add the tomatoes, molasses, 1/2 teaspoon of salt and lots of freshly ground black pepper. Stir, bring to a boil, then cook at a generous simmer about 10 minutes until thickened. You can puree it if you like. Set it aside to cool and then jar. Store in the refrigerator.
7. Combine the cinnamon sticks, cloves, green cardamom seeds, black cardamom seeds, if using, in a spice grinder or coffee grinder and grind until fine. Store the spice mix in an airtight container away from direct sunlight.