Black Pepper is native to much of Asia, and was often used as the primary spice in parts of India. Other spices such as cloves, nutmeg, cinnamon, ginger were also heavily used. The oldest text about cooking I know of from South Asia is the Soopa Shastra from the early 1500s. That might be a place to look to find out what Indian food was like before the Colombian exchange.

I'm very curious about pre-pepper Kimchi...

The Arabs had been conducting trade in spices with India long before the 1500s.