Film a stock pot with vegetable oil and place over moderately high heat. Brown sausage on all sides. Reduce heat to low and cook through, eight to ten minutes. Remove sausage from pan and cool. Discard grease. In the same pan, add olive oil and pancetta over low heat until crisp, about seven to nine minutes. Add onion and cook until soft and translucent, five to six minutes. Add garlic and saute until golden, about three minutes. Add remaining ingredients, increase heat, and bring to a boil. Dice reserved sausage and return to chili mixture. Lower heat and simmer until beans are tender, at least 90 minutes, stirring occasionallly. Season with salt and pepper to taste. Serve each bowl of chili with a dollop of sour cream and some green onions and fried leeks. Serves 4 to 6.

*Fried Leeks: Bring water to boil and blanch leek threads for five to eight seconds. Strain and squeeze excess moisture from leeks, patting dry with paper towels. In a large skillet, heat canola oil over high heat until almost smoking. Add leeks and fry until they just start to turn golden brown. Drain on paper towels. Season with salt.