From Nepal, this looks like a fabulous dish for the World Tour.
Mustard oil is an extremely hot, pungent oil expressed from mustard seeds and should be stored in the refrigerator and will keep for up to about 6 months. It can be used (sparingly because of the heat) in stir fries, salad dressings and marinades.
Stone ground prepared mustard could be used as a substitute.
From North India. If you're like me & enjoy experimenting, go to the nearest Indian store (or online) & order up as many kinds of dal as you can & then find ways to use them! This was posted on a vegetarian website & I like the recipe so I swiped it to share here. Once you have the ingredients, it's a breeze to make! **The 2 hour soak time is NOT included in the cook time**