Coat pork with flour by placing it in a paper bag and shaking.
In a large pot, heat oil over medium-high heat for 2 to 3 minutes. Add pork and cook until golden brown, for about 5 to 7 minutes.
Pour in half of the chicken stock and bring to a lively boil, then lower the heat to medium and simmer for 15 to 20 minutes.
Puree diced tomatoes until smooth in a blender. Mix the puree into the pot with the rest of the chicken stock, green chile and jalapeno peppers, garlic, onion powder, garlic powder, garlic salt, cumin, and black pepper. Simmer gently for 1 hour.
For a thicker chili, blend water and cornstarch, then whisk into boiling chili. Simmer until thickened before serving immediately.