i'm planning on making the Irish Stew from The Single Vegan for St. Patrick's Day dinner. the recipe calls for 1/2 teaspoon yeast extract. (it's a British cookbook.) what is that, marmite or vegemite or something? could i substitute the same amount of nutritional yeast for the extract, or is the taste/texture too different? or should i just leave it out? i don't want to buy a whole thing of yeast extract just to use this miniscule amount.