Trim The Chicken Of Any Fat And Cut Into Chunks. Heat Half Of The Butter In A Large Skillet Set Over Medium-High Heat. Add The Chicken In Batches And Brown All Over. Transfer The Browned Meat To A Plate. Reduce The Heat To Medium. Add The Onion And Garlic To The Pan. Cook, Stirring Often, Until Golden, About 8 Minutes. Stir In The Tomato Paste, Curry Paste, Ginger And Cinnamon. Cook For 1 Minute. Stir In The Ketchup, Yogurt, Cream, Chicken Pieces And Any Juices That Have Accumulated On The Plate. Simmer, Partially Covered And Stirring Occasionally, For 15 Minutes Or Until Chicken Is Tender And Sauce Is Thickened. Stir In The Remaining Butter, Lime Juice And Lime Zest Just Before Serving. Serve Over Basmati Rice And Garnish With Chopped Coriander (If Using).