Szechuan peppercorns are featured mostly in the cuisines of Northern China. They are not true peppercorns but the dried berries of a member of the citrus fruit family, delivering heat and flavor, "ma la," a spicy tongue-numbing effect with a fragrance more akin to rosemary or lavender.
It used to be very hard to find--I think it was banned ignominiously and unjustly accused of carrying a sort of plant blight--but it is once again available in store shelves.
Store the peppercorns in a dry, well-sealed container and they keep indefinitely.
They must be dry-toasted then ground to extract flavor:
Toast the amount you need in a dry pan over medium heat until brown, around 5 minutes. Remove from heat, let cool and grind.
The following recipe, highlighted by the pungent flavor of Szechuan peppercorns, is a favorite cold-weather dish of our family.
Ken Hom's Twice-cooked Pork
To a large pot of boiling water, add 2 to 2 &1/2 pounds of pork belly and add 6 slices of ginger and 6 whole scallions. Cover tightly and simmer for 1 &1/2 hours; remove the meat, drain well, and let cool thoroughly. Slice into 1/4 inch pieces.
Heat a wok until very hot but not smoking. Add 3 tbsp. of peanut oil and the pork slices and stir-fry for 10 minutes. Drain off any excess oil. Add 2 tbsp. finely minced garlic and 1 tbsp. of finely chopped peeled fresh ginger and stir-fry 10 seconds. Add 3 scallions(3-in. pieces), continute to stir-fry 3 minutes. Then add: 1 &1/2 tbsp. chili bean sauce, 1 tbsp. rice wine, 1 tbsp. light soy sauce, 2 tsp. sugar and 1 tsp. salt and stir-fry 3 minutes more, mixing well. Serve hot...
with lots of rice.