Make the sauce: In a blender, purée tomatoes, onions, ginger, garlic, and serrano pepper.
Pour this into the slow cooker. Set aside blender container.
Add chana masala, turmeric, salt, cayenne, coriander and cumin to the tomato onion mixture in the slow cooker.
Add in drained soaked chickpeas and the chana dal (split chickpeas).
Pour in two cups of water into the blender container, slosh it about to get all the saucy goodness, and pour this into the slow cooker.
Cook on high for 6 hours or until the chickpeas are soft and well cooked.
When the beans are cooked, use the back of your spoon to mash a few of them to thicken the chana masala.
Stir in the tamarind paste, lemon juice, and cilantro, and serve.
Be sure to soak the chickpeas for this recipe. Either soak them overnight or use my quick tip which is to soak them in hot water. Either boil the water or use the hottest water from your faucet and soak them. They plump up in an hour and it's as good as having soaked them overnight.
Do not add the tamarind at the beginning of cooking. It will make your chickpeas super tough and not fun.
Traditional chana masala uses amchoor powder. I used lemon juice in this recipe but if you have the amchoor powder, go ahead and use it.
Buy the chana masala spice mix for this recipe--trust me, it's a lot easier than buying 20 different spices to make your own.
Use split chana dal to make your chana masala thicker. If you choose not to buy this, you can either let the curry be a little thinner, mash some of the chickpeas into the final dish, or use a can of chickpeas to add thickness.
You can also make this with canned chickpeas but it takes just a little more intervention. Cook the vegetable mixture with 1 cup of water for 4 hours on high Or 6 hours on low. Then, add in drained canned chickpeas, add in another cup of water and allow it to cook for another hour on high.
You can use either fresh or canned tomatoes, fire-roasted or regular canned tomatoes. Don't bother with expensive canned tomatoes since there are so many other flavors in this that will overpower the tomatoes.
This recipe does very well in the fridge or in the freezer. The flavors get better and better over time. It also thickens over time though, so you may need to add some water to reheat.
Slow Cooker Chana Masala https://twosleevers.com/slow-cooker-chana-masala/