Spicy Stewed Potatoes & Spinach with Buttermilk (Aloo chaas)

Spicy Stewed Potatoes & Spinach with Buttermilk (Aloo chaas)
This stewlike potato and spinach curry can be served as a side dish or as part of a vegetarian buffet. The touch of cream prevents the buttermilk from curdling when it's heated and helps balance the heat from the pungent chiles.