Heat 2 tablespoons extra-virgin olive oil in a large skillet over medium heat. Add 1 medium yellow onion (chopped) and cook, stirring often, about 8 minutes, until the onion is soft and well browned.
Reduce the heat to medium-low. Add 1 teaspoon cumin seeds, 1 teaspoon garam masala, ½ teaspoon ground coriander, ½ teaspoon ground turmeric, ¼ teaspoon ground cardamom, and a pinch of cayenne pepper. Stir and cook about 30 seconds, until the spices are fragrant.
Stir in 2 grated garlic cloves, ½ teaspoon grated fresh ginger, and a heaping 1 teaspoon sea salt. Add ¼ cup of the ½ cup water and stir to loosen any browned bits from the pan.
Add the (28-ounce) can whole peeled tomatoes, breaking them apart with your hands as you add them or crushing them with a wooden spoon in the skillet. Bring to a simmer and cook 8 to 10 minutes, stirring occasionally, until the sauce thickens.
Add 3 cups cooked chickpeas (drained and rinsed) and the remaining ¼ cup water. Stir to combine, then simmer gently, uncovered, for 20 to 25 minutes, stirring occasionally, until the mixture has thickened and the flavors meld.
Remove from heat and stir in ½ cup chopped fresh cilantro and 1 teaspoon fresh lemon juice. Taste and, if desired, add more lemon juice or a little more salt.
Serve the chana masala over cooked brown rice or white rice with dollops of whole milk Greek yogurt and additional cilantro and lemon juice for garnish, if desired.