Creating One-Pot Lamb Kalya with Yogurt and Cream is simple when you follow these steps:

1. Heat Oil: In a large pot or Dutch oven, heat the vegetable oil over medium heat.
2. Sauté Onions: Add the chopped onion and sauté until golden brown, about 5-7 minutes.
3. Add Garlic and Ginger: Stir in the minced garlic and grated ginger, cooking for an additional 2 minutes until fragrant.
4. Spice It Up: Mix in the ground cumin, ground coriander, turmeric, garam masala, and red chili powder. Cook for another minute to toast the spices.
5. Brown the Lamb: Add the lamb chunks to the pot, stirring to coat them in the spice mixture. Brown the lamb on all sides.
6. Add Tomatoes and Water: Pour in the diced tomatoes and water or broth. Stir to combine and season with salt.
7. Simmer: Bring the mixture to a boil, then reduce the heat to low. Cover the pot and let it simmer for about 1 hour, or until the lamb is tender.
8. Stir in Yogurt and Cream: Once the lamb is cooked, remove the pot from heat. Stir in the plain yogurt and heavy cream until well combined.
9. Adjust Seasoning: Taste and adjust seasoning if necessary, adding more salt or spices according to your preference.
10. Garnish and Serve: Sprinkle fresh cilantro on top before serving, and accompany with lemon wedges for an extra zing.

This step-by-step guide will help you create an incredible One-Pot Lamb Kalya with Yogurt and Cream that is sure to impress!