Split peas are the dried, hulled and split seeds of the field pea (Pisum sativum), the same species as the garden pea but grown to full maturity and dried on the plant rather than picked green and sweet. Once dried the round pea is mechanically rubbed to slip off its skin and split along its natural seam into two flat half-discs, which is why split peas need no soaking and cook far faster than a whole dried bean. They come in two colours — the familiar muddy-green split pea and a golden-yellow type — and both cook down into a thick, soft, comforting puree with a faintly sweet, earthy, almost meaty savour. That collapse into a coarse, starchy mash is the whole point: split peas are the soul of split-pea soup, of British pease pudding, and of much of Indian dal, where they are simmered with aromatics and fat into something warming and cheap and deeply satisfying.