A specialty of butchers throughout Cajun country, boudin is a sausage of pork, rice, onions, and spice. It is not firm like an Italian sausage. Once cut, it tends to spill, tumble, or gets squeezed out depending on the link’s consistency. It comes in shades of beige, hot ones tinged pepper red, some speckled with a confetti of green and yellow onion. Differences among them can be subtle. Are the rice grains firm or soft? Is the pork pulverized or rough-hewn? Does it glisten? Does it have a sweet, fresh smell? Does the filling drip unctuously or is it dry?