Indian stews, curries and lentils perform so well in a slow cooker that if you don’t have one of the numerous cookbooks on using slow cookers for Indian food, you really should seek one out.

That countertop appliance can help you create rich, decadent sauces and legumes that you never thought you could make at home, but you might have to make a trip to the Indian market (or get lucky at your nearby bulk spice department) to find some of the distinct flavors. (Fenugreek or curry leaves and really fresh garam masala are three of them.)

As Bombay-born author Neela Paniz explains in her new book, "The New Indian Slow Cooker: Recipes for Curries, Dals, Chutneys, Masalas, Biryani, and More" (Ten Speed Press, $19.99), this tomato butter sauce is the basis for what we now call tikka masala, a versatile name for a wide range of dishes that almost always contain chicken. Paneer and tofu, seared in a pan before tossing in the sauce, are fine substitutes, and like many Indian curries, this is best served with fresh basmati rice.

Tomato-Butter Sauce

Chicken tikka masala has become an international phenomenon served in Indian restaurants all over the world. The original recipe, known as butter chicken, came from one of the first tandoori restaurants in Delhi, Moti Mahal. Tandoori chicken pieces were added to tomato-cream sauce and served with naan, tandoor-baked flat bread.

Here is the simple yet delicious recipe for the makhni, or butter sauce. One can then add grilled marinated chicken or even just sautéed pieces of boneless chicken, to make chicken tikka masala.

— Neela Paniz

6 Tbsp. butter

1 cup heavy cream

1 cup half-and-half

1/4 tsp. saffron threads (optional)

2 (28-oz.) cans tomato sauce, preferably without salt

1/2 cup water

1 (2 1/2-inch) piece fresh ginger, peeled and minced

2 or 3 serrano chiles, minced

1 1/2 tsp. garam masala

2 Tbsp. roasted ground cumin

3/4 to 1 tsp. ground Indian red chile

1 1/4 tsp. salt

4 Tbsp. sugar

2 Tbsp. dried fenugreek leaves (optional)

2 heaping Tbsp. chopped cilantro

Heat the cooker on high and add the butter to melt. This will take about 10 minutes.

Add the cream and half-and-half to the melted butter. Add the saffron, if using, and mix well. Add the tomato sauce, then rinse the cans with 1/4 cup of water each to get all the sauce; add this to the cooker. Add the ginger, serrano chiles, garam masala, cumin, ground red chile, salt, sugar, and fenugreek, if using, and mix well. Cover, reduce heat to low, and cook 6 hours. When ready to serve, stir in the chopped cilantro.

Cool any unused sauce to room temperature and store for later use — either in sterilized jars for up to 2 weeks in the refrigerator or in plastic bags, with all air removed, in the freezer for up to 3 months. Makes 2 1/2 cups.

— From "The New Indian Slow Cooker: Recipes for Curries, Dals, Chutneys, Masalas, Biryani, and More" by Neela Paniz (Ten Speed Press, $19.99)