Heat the oil in a large saucepan over medium-high heat until it shimmers. Add the onion, garlic and chili peppers, and saute until the onions brown around the edges.
Add the ground beef and 1/4 cup water. Cook the beef, stirring to keep it from clumping up, until it's completely browned.
Add the beans and the tomato puree and raise the heat a little. Cook everything until the tomato puree browns.
Lower the heat to medium low, and add all the other ingredients. Bring it to a boil, and simmer for about 45 minutes, or until the sauce thickens enough to pick up with a fork.
