Smoked picnic shoulders are a smaller cousin to hams, cured in the same way and tasting very similar. The difference is that hams come from the meatier hind leg, while picnic shoulders come from the front leg. Smaller than hams, shoulders are often cut into halves to make them a better size for smaller families. They're often baked like hams, but another popular preparation method is to simmer the shoulder in water or broth. Smoked shoulders are almost always sold fully cooked, and are tender and ready to serve once they're warmed all the way through.
Place the picnic shoulder in a large pot, and cover it with cold water, broth or a mixture of the two. Bring it to a boil, then reduce the heat to a gentle simmer.
Add onions, spices or other flavoring ingredients to the pot. Cover the pot and simmer the shoulder until hot through, approximately 1 1/2 hours for the shank portion or two for the butt portion. If you're boiling a whole shoulder, allow up to three hours.
Open the pot 20 to 30 minutes before the end of your expected cooking time, and insert a meat thermometer or instant-read thermometer into the thickest part of the shoulder. If the shoulder was already cooked and in its original packaging, it's considered food safe after it reaches an internal temperature of 145 degrees Fahrenheit. If it was uncooked, it should reach 160 F.
Remove your thermometer and resume simmering, if the shoulder has not yet reached the correct temperature. You might also choose to cook the shoulder longer if you wish it to be fork-tender. In that case, test it periodically by inserting a fork into one of the muscles and twisting. When it twists freely and removes a forkful of flesh, the shoulder is done.
Drain the shoulder, reserving the cooking liquid for soup or for imparting flavor to boiled vegetables. Let the meat rest for at least 10 to 15 minutes before slicing and serving it.
To make a traditional New England-style boiled dinner, add carrots, potatoes, cabbage, turnips or other vegetables to the cooking water and simmer them until they're tender. Serve the ham-scented vegetables alongside your shoulder. If you have leftovers, they'll make excellent hash for the next day's breakfast or lunch.