I would like to know if it is at all possible to make tandoori roti with chick-pea or green pea flour. Also is it just as simple as grinding dry peas into fine dust and using it as a substitute for flour or is there more to it than that. Also, what would you use as binding agent? 
You can make a sort of bread with chickpea flour. It's a bit dense compared to a regular chapatti or roti & I'm not sure how much good it would be for picking up your main dish.  By volume, use 50:50 ratio flour to water, add salt to taste. Mix, pour onto baking paper on a flat try & bake at 200 until the sides start to brown. 15 - 20 mins.  Given the choice, I'd make pakora or bhajis instead. The batter fluffs up better deep fried than in the oven.  Chick pea flour is also called gram flour or besan &, at least in the UK, can now be found in any supermarket. I've never used green pea flour, so can't really comment. 