Sprinkle coriander over cut chicken; mix it well so that all the chicken surfaces have some coriander on them. Set aside to rest.
In large skillet or dutch oven, heat ghee (butter) and 2T olive oil. Add onions to pan; sauté for 2 minutes. Add garlic and remaining vegetables; sauté five minutes. Sprinkle in curry powder and turmeric and cook 1 minute. Sprinkle in flour and cook 1 minute. Stir in chicken broth and milk; cook, stirring, until sauce thickens slightly. Remove from heat and stir in yogurt. Pour into large mixing bowl and set aside.
Using the same skillet, add 2 T olive oil and return to med-high heat. When oil is hot, add chicken pieces in smallish batches so that you sear them, but you do not need to cook them through. Remove each batch from the heat and stir into waiting veggie/broth mixture. Repeat until all chicken pieces are nicely seared.
With skillet still on the heat, pour in Marsala to deglaze the pan. You may also add a little cold water if needed to loosen all the little tasty bits of veggies and chicken. Cook, stirring constantly, until liquid is reduced to half (it should appear creamy) then pour the pot liquor into the bowl with the chicken and veggies. Stir well.
Pour the entire bowl into greased casserole dish (I used a 10x15 4qt pyrex baking dish).
Bake, uncovered, 45 minutes.
Serve with steamed rice or prepared couscous and Naan bread.