Quick Chana Masala

Name: Quick Chana Masala
Ingredients: 1 large red onion; plus more thinly sliced for serving (optional); 2 plum tomatoes; 2 15-oz. cans chickpeas (do not drain); 3 Tbsp. vegetable oil; 1 tsp. cumin seeds; 6 garlic cloves, finely grated; 1 1 piece ginger, peeled, finely grated; 2 tsp. garam masala; 2 tsp. Diamond Crystal or 1¼ tsp. Morton kosher salt; 1 tsp. ground coriander; ½ tsp. amchur (dry mango powder); ½ tsp. ground turmeric; ½ tsp. Kashmiri or other red chile powder; ⅛ tsp. ground cinnamon; Juice of ½ lime; ¼ cup chopped cilantro, plus leaves with tender stems for serving; 2 Tbsp. unsalted butter (optional); Steamed rice, naan, or crusty bread (for serving)