Milk Street Facebook Community member Bhakti Pathak of Mumbai, India, makes aromatic, golden-hued mashed potatoes by toasting turmeric and other spices, then folding them in at the end. To coax the fullest flavor out of the seasonings, we make a tarka, a mix of spices and, oftentimes, other aromatics that are bloomed in hot fat. The technique comes from the Indian kitchen, and tarka can be used either to build foundational flavor in a dish or to finish it when cooking is complete, as with these mashed potatoes. To crush the mustard seeds and cumin seeds, either bash them with a pestle in a mortar, of pulse them a few times in an electric spice grinder.