Bhagari Jhinga (Indian Stir-Fried Shrimp in Cream Sauce)

Ingredients

• 1 Tbsp fresh tomatoes
• 1/2 tsp salt
• 1 tsp white sugar
• 1 tsp garam masala
• 1/2 tsp ground cumin
• 1/8 tsp ground red pepper
• 3 Tbsp finely chopped fresh cilantro
• 1 fresh green chili
• 1 Tbsp fresh lemon juice
• 1 c yogurt or fresh coconut milk
• 3 Tbsp vegetable oil
• 1 tsp black mustard seed
• 1 1/4 lbs medium shrimp - peeled and deveined
• 1 Tbsp cornstarch
• 1 Tbsp cold water