Marinate as you would fried chicken in buttermilk. But use the tandoori spiced yogurt. Yogurt and buttermlik are similar enough for this purpose.
Breading, well, I'd have to go with a pakora type breading based on besan/chickpea flour just to keep with the whole indian thing. If not tha, then just the standard flour with some tandoori/garam masala spices in the flour. Probably some paprika or annato powder for color there too.
Phil |