Cut off and discard the tough stems and discolored leaves from the greens. Cut across the leaves into 2-inch ribbons.
In a large stock pot, over medium-high heat, add the canola oil and the diced salt pork, and cook until light golden brown and just crisp. Remove to a paper towel lined plate and let cool.
Add the onion to the pot and cook until translucent, about 5 minutes, then add the red chili flakes, black pepper, and the collard greens.
Stir every few minutes, or until greens have wilted down. Add the chicken stock and the water and cover. Cook for 30 to 45 minutes, then remove the lid, increase the heat to high, and add the vinegar and a teaspoon of hot sauce. Adjust the seasoning, if needed, then put it into a serving bowl. Sprinkle with the salt pork and serve with additional hot pepper sauce on the side.