Combine first 8 ingredients in a small bowl. Heat oil in large, deep skillet set over medium, medium-high heat. Add the onions and cook until tender and light golden, about 5 minutes. Mix in spice mixture, tomato paste, ginger and garlic. Cook and stir 2 minutes more.
Mix in diced tomatoes and stock, bring to a gentle simmer, and cook 5 minutes. Season the chicken with salt, and then stir into the sauce. Simmer until the chicken is cooked through and the sauce has thickened, about 12 minutes. Stir in yogurt or cream and heat through 1 minute. Taste and adjust seasoning, if needed, and then serve. If desired, garnish servings of the chicken with cilantro sprigs.
Garam masala is an Indian-style spice blend available in our bottled spice aisle.
Add a little mango chutney
Mango chutney could be a condiment for the chicken and you can buy it in jars in our stores. You could also make fresh mango chutney. To do so, combine 1 cup finely cubed ripe mango, 1 finely chopped small tomato, 2 Tbsp. finely chopped onion, 2 Tbsp. chopped fresh cilantro or mint, 1 Tbsp. fresh lime juice, 1 tsp. sugar, and salt to taste in a bowl.