Lamb Keema with Potatoes and Peas

2 tablespoons olive or vegetable oil
1 medium onion, chopped
2 garlic cloves, minced
1 small serrano chile, minced
About 1 tsp. salt
1 teaspoon ground cumin
1 teaspoon ground coriander
1 1/2 teaspoons garam masala
1/2 teaspoon pepper
1 tablespoon tomato paste
1 1/2 pounds ground lamb
2 medium Yukon Gold potatoes, cubed
3/4 cup plain yogurt
3/4 cup whole milk
3/4 cup frozen peas
Hot cooked rice
1/2 cup chopped cilantro

1. Heat oil in a large pot over medium-high heat. Add onion and cook, stirring occasionally, until softened, 3 minutes. Add garlic, chile, 1 tsp. salt, and the spices; cook 2 minutes longer. Stir in tomato paste.
2. Add lamb and cook, breaking up large chunks of meat, until no longer pink, about 3 minutes. Add potatoes, yogurt, and milk to pan and bring to a boil. Reduce heat until mixture is simmering vigorously, cover, and cook 10 minutes.
3. Stir in peas and cook 5 minutes longer, until peas are cooked through and mixture has thickened. Serve over rice with cilantro sprinkled on each serving. Add more salt to taste if you like.