Soak the bread or cracker crumbs in 1/3 cup of the cream. Put 1 tablespoon of the butter in a large skillet over medium-high heat. Add the onion and a bit of salt and pepper and cook, stirring occasionally, until the onion softens, about 5 minutes. Turn off the heat.
Combine the bread crumbs, onion, meat, and spice, along with some more salt and pepper; do not overmix or overhandle. With wet hands or wet spoons, shape the meat into small meatballs (I would say as small as you have the patience for, but no more than an inch in diameter).
Put 2 tablespoons of the remaining butter in the skillet and turn the heat to medium-high. When the butter melts, begin adding the meatballs, a few at a time; you may have to cook in batches. Brown nicely on all sides and turn off the heat. Serve immediately or proceed to the next step.
To make a sauce, remove all but a trace of fat from the pan. Return the pan to the stove over medium heat and add the remaining butter and, after it melts, the flour. Stirring constantly, add the stock and cook until slightly thickened. Add the remaining cream and continue to cook for a few more minutes or until thickened. Taste and adjust the seasoning, then pour the meatballs into the sauce to reheat before serving.