1. Slice the chicken breasts into bite-sized chunks or slices. Add to a large container with 1/2 – 3/4 c. of the plain Greek yogurt, and about half the garlic, ginger, paprika, garam masala, and cumin. Sprinkle with salt & pepper. Combine well and let marinate for a few hours.
2. In a large fry pan, over medium-to-high heat, add a bit of oil and fry half of the chicken breasts pieces until golden brown on each side. Remove from heat temporarily. Complete this with the other half.
3. In the same pan, add bit of oil and fry the onions until translucent. Then, add in the tomatoes and the rest of the garlic, ginger, and seasonings. Fry until the tomatoes break down. Transfer the mixture to a blender or use an immersion blender if available, and blend until smooth.
4. Add in a few dollops of yogurt until it reaches the desired creaminess.
5. Adjust for flavours with any of the seasonings. Optionally add some heat with a red chili pepper!
6. Sprinkle over just a bit of lemon juice.
7. Garnish with cilantro and serve with rice and or naan!