curry is improvised from an old
Joy of Cooking rule for stew and
various hints thrown out by my brother-in-law Simon, who makes a fine
curry, refined during his years in Kenya. (His goat curry, served at a
picnic by a river on the edge of the Nairobi Game Park, was my first
meal in East Africa, sometime in the last century.)

only real secret to simple, reliable curry, however, is Patak's Curry
Paste, available at many local supermarkets, worth tracking down at a
specialty store if not.  (It can be had via Amazon as well.)  You need a jar of mild and a jar of hot, so you
can mix to taste.

with some vegetable stock. This used to be collected from the run-off
of boiled vegetables of every kind, but since we now steam our
vegetables, the liquor from soaked and boiled dried beans is a good
substitute, especially for curry. Pour enough of it into a stew pot to
comfortably cover the meat and vegetables you will be adding — lean
chunks of lamb, or goat (I like to use chunks cut off of thick lamb
chops, with all the fat removed, but there are cheaper ways to go), an
equal volume of pearl onions, an equal volume of carrots cut into
pieces about the size of pearl onions, an equal volume of potatoes, cut
into chunks of a similar size, and three or four tablespoons of peeled
and chopped ginger root.

to warm the vegetable stock and stir in table-spoonfuls of curry paste.
I like a 2 to 1 hot to mild ratio, for a very — very — spicy but not
searing flavor, but do it to taste. About six table-spoonfuls at least
will be required. You can tell by tasting when you've got enough.

this mixture to a boil, then throw in the ginger and the carrots, cover
tightly and reduce heat to produce a steady but not furious bubbling.
After ten minutes, put in the lamb. After another ten minutes, put in
the onions and the potatoes. After another twenty minutes, cut off the
heat, let the pot cool, and then put it in the refrigerator overnight.
(This must be made the day before it is eaten.)

is a dish to fiddle with — placing the lamb in later if you like it
rarer, the carrots in later if you like them crisper, the onions and
potatoes in earlier if you like them mushier, more or less ginger and
curry paste.

next day, put what you want to eat into a smaller pot (you can freeze
what's left, if any) and heat it up, thickening it with some dollops of
sour cream if you like. Serve it over basmati rice, and no other kind,
with, on the side, some mango chutney and raita — plain yoghurt and
peeled, thinly sliced cucumbers, chilled — and some kind of plain
bread (real Indian bread, like poori, is best but too hard to make.)
Drink beer with it.