Search on Kala Namak which is a synonym for black salt. It is used in Chaat dishes and Riatas. If you start down this road plan on a trip to the Indian market to get some other ingredients.

Like Phoxx says, chaat recipes use black salt. You could also try them in the oven roasted chickpeas recipes that was on this site sometime ago. May be on popcorn. It does have a tangy taste, so you may want to start with less and add as per liking.

Sometimes I add it to chickpea pancakes.

Believe it or not, many Indians add it to soda and lemonade (myself being one :) ). It's great on top of cut veggies paired with some lemon juice -- carrots, cucumbers and tomatos especially. Also good on watermelon (I love the sweet/salty combo)

I used it in this "green dal" with moong dal, spinach, jalapenos, cilantro, lime...
http://outoftheordinaryfood.com/2012/03/28/homemade-paneer-green-dal-tomato-cashew-curry/

I think you could add it to any sort of dal or curried chickpea dish and it would taste good. It just adds a sort of sulphury kick to a dish.

Try making fruit chaat!

These ideas are awesome, thanks! Despite having spent the better part of a year in India and collecting Indian recipe books (including some that I bought there), I haven't come across an Indian recipe that includes kala namak.

Not sure how you've used it in vegan breakfast recipes so far- It's great in tofu scramble, tofu omelet and tofu "egg" salad (or use mashed chickpeas)

They're great on top of idlis, freshly cut vegetables w/pepper (cucumber, daikon, carrots, etc) as a snack and papri.

You can sprinkle on anything to give it flavor. Sprinkle in salads, fruits, buttermilk, soda(lemon), watermelon, pocorn, Sprouts, savory pancakes, sandwiches. Guacomole, Salsa(Personal favorite)
Being an Indian, I would say, don't cook with it(I don't know why but that's how I have seen it).

Any savory dips.

I love kala namak. My great aunt introduced me to it and said it's good for digestion. We put it on a lot of Indian dishes, but I've started mixing it into my plain flavored kefir and it's delicious!

Hi there we use it in chutney
Mint and green mango chutney
http://www.asankhana.com/2012/09/my-love-for-kababs-chicken-shami-kabab.html

Here are a few recipes you can have a look at which use Black Salt (Kala Namak) while preparing them.

Black Salt (Kala Namak) Recipes