Dice the onion and chipotle chile, and press the garlic. Set aside.
In a large, heavy skillet, cook the ground beef, onion, garlic and salt over medium high heat until the meat is cooked through and no longer pink. While cooking, break the ground beef into small pieces with a spatula. Once the meat is cooked, drain the meat/onion mixture using a colander.
Return the meat mixture to the skillet and add the chipotle chile, chile powder, oregano, and cumin. Cook and stir over medium high heat for 2-3 minutes over medium high heat until the spices are mixed throughout and beginning to toast.
Add the tomato sauce and water, along with the agave syrup, honey, or sugar (optional), and stir until well blended.
Reduce heat to low. Simmer the meat and sauce for about 15 minutes or until most of the water has evaporated.
While the taco filling is simmering, taste and adjust seasonings to your taste.
Serve in hard or soft taco shells with your favorite toppings, such as shredded cheese, sour cream, salsa, guacamole, shredded lettuce, diced tomato, diced white onion, or chopped cilantro.