From: Mark Bittman
The standard procedure for classic croquettes is to make a thick milk-butter-and-flour béchamel sauce, add the minced or shredded chicken and chill it into solidity. Then you form your shapes, bread them and fry them. But the best ones that Jackie and I ate on this trip had a more pervasive chicken flavor than that, and when we got home I made my sauce with half milk and half chicken broth, generated by poaching the chicken. Here’s what to do to make 16, four-bite croquettes. You need to make the mixture a good five hours before serving — the day before would be ideal.
Put two small whole, skin-on chicken legs into a pot with a carrot, half an onion, half a clove of garlic and two inches of celery, all roughly chopped. Add fresh parsley, a bay leaf, a few peppercorns and some salt. Cover with water, bring to the boil and lower the heat to a simmer — the liquid should still be gently bubbling. Simmer for 30 minutes or so, until the chicken is tender, and let everything cool in the pot.
Make a thick béchamel sauce: finely mince a tiny onion or a shallot, to yield two or three tablespoons. Melt four tablespoons butter in a small saucepan and sweat the onion over low heat for three or four minutes until soft. Whisk in four tablespoons flour (or 4-1/2 if you want the croquettes to be easier to handle if not quite as oozy) and cook for around five minutes — don’t brown this roux. Now gradually whisk in 3/4 cup each of whole milk and chicken broth (from cooking the chicken legs). Simmer over very low heat for about ten minutes, frequently stirring/scraping with a rubber spatula or a whisk — it will be quite thick and smooth. Add salt, pepper and nutmeg to taste.
Meanwhile, pull the meat off the chicken legs, discarding bones, skin and tough connective tissue. Shred it with your fingers (which will enable you to detect and get rid of any bits of kneecap or tendon), then chop fairly fine with a knife. You could just chop it up, but you want that somewhat fibrous, shredded texture.
My two small chicken legs yielded 1-1/2 cups of chopped shredded meat, which was about right — but a little more wouldn’t hurt anybody. Mix it into the sauce, optionally adding some minced prosciutto-type ham (ideally Spanish, but don’t fret if you have to draw on another source — and use enough so that you can taste it). Cool, cover and place in the refrigerator to solidify, a process that can be sped up up by using a shallow dish rather than a deep container.
When it is cold and quite solid, line a tray or plate with waxed paper and form 16 two-tablespoon balls of the mixture — you could also make them a little smaller, but my mini-ice-cream scoop happens to be that size. Put this in the fridge while you prepare three bowls: one with some flour for dredging; one with a beaten egg; and one with plenty of crumbs made from good semi-fresh bread (I use Sullivan Street Bakery’s Pugliese loaf for the crumbs that take up quite a lot of my freezer). With your hands, roll each ball into a rough cylinder, then run it in turn through the flour, the egg and the crumbs. Leave aside while you heat a good two inches of neutral oil (possibly supplemented with some olive oil for flavor ) to between 325 and 350 degrees Farhrenheit — but no higher than that: you don’t want them to brown too much before they’re heated through.
Fry, in batches depending on the size of your pan, for about five minutes, turning once or twice to ensure even browning. Drain on paper towels and transfer to a platter. They will remain very hot inside for ages, so eat carefully.