Mustard seeds add piquancy and texture to many dishes. Mustard seeds are used in a huge number of Indian dishes, often fried in oil until they start to pop, then the spiced oil is either poured over a finished dish or used as a base to cook the other ingredients. Brown mustard seeds are slightly smaller and hotter but the difference is marginal and may come down to aesthetic preference. Black mustard seeds are larger and very pungent - ideal for many Indian recipes although brown seeds are often as suitable.uses: Add to a dressing or mayonnaise for heat and texture. Fried in oil the mustard seeds are superb when mixed with green vegetables or potatoes. Crush with coriander seeds, fennel seeds, salt and pepper to make a delicious crunchy spicy crust for fish, meat or roast vegetables.