Combine all the ingredients in a jar. Mix. Cover with a tight lid.
Store away from heat and sunlight.
Makes 7 tablespoons.
For The 19th Century British Curry Powder
Put the coriander seeds, split peas, peppercorns and cumin into a medium cast iron frypan and set on medium heat. Stir and roast until the split peas are reddish, the coriander has turned a shade darker and all the spices begin to give off a roasted aroma.
Empty them into a bowl and allow to cool.
Put the roasted spices and the mustard seeds into a spice grinder or food processor and grind as finely as possible. Place in a bowl.