Indian cookery - Mustard seed query

[cyanarasamba]

I'm going to have a go at making Saag Aloo for dinner. The recipe calls for black mustard seeds, but naturally my huge Tesco didn't have these, only yellowy ones. Will it ruin the taste if I use these and should I just leave them out?

I make saag aloo but never used black or even yellow mustard seeds.

leave them out. You need the black ones, but it will be fine wihtout.

Yellow would be okay - it is a nice spice, maybe just slighly less pungent than black.