Butt-ends of celery. And fennel—the stalks as well.
Coarse outer leaves of everything lettuce, especially escarole.
Radish tops and kohlrabi tops. (The colour of beet tops is off-putting.)
Plucked-clean stems of kale, collards, parsley.
Also, discarded stems and twigs and woody parts of any herbs.
Tips and skins of garlic, shallots, onions.
Peelings from nearly everything. Carrots, ginger, summer squash, of course, but no starchy stuff. No potato or sweet potato.
Cabbage leaves? bottoms of brussels sprouts? cauliflower? broccoli?—tempting, but too strong; they will sink whatever they touch.
Can’t get too much of carrots and celery. Brown, spotty, limp, rubbery, hairy, all do fine.
Squash seeds, apple cores.
Rinds of hard grating cheeses—judiciously.
Collect in a bag and bung in the freezer.
When the bag holds as much as the stock pot will hold—this takes two weeks to a month—cram the whole shooting match into the pot, fill it with water and boil for an hour.
The resulting stock has many uses, in gravies, sauces, soups, but mainly for cooking beans.
I speak here mainly of the mild, white, sort of beans. Navy, pea, great northern, white kidney, above all the noble cannellini (when they can be found). Occasionally cow peas or chick peas, or pinto beans. Never the red kidney.
My way is the way of the so-called quick soak, which is to say, boiled briefly and left to cool over two or three hours.
Discard this first water (and with it, one hopes, some of the natural hazard of beans), and rinse.
The second, serious cooking of the beans is in the prepared vegetable stock. Always different, according to the season and the chances of the kitchen.
For about an hour.
Questions of salt (added early or late), of a bay leaf or two, perhaps some rubbed sage, whether to leave the pot lid on or off.
The lid off makes the most intense flavour, but the pot must be watched, a degree of absorption in the task only warranted, in my view, when cannellini are at stake.
The beans are eaten drained, tossed with olive oil and lemon, and perhaps some braised kale, the black Tuscan variety.