Roughly chop 1/2 onion and sauté onion in a dollop of oil over medium-high heat for a few minutes.
Add ground beef and cook until browned. Drain any fat if you want.
Add 1 clove minced garlic and saute briefly.
Add 1 minced chipotle and 1 tablespoon adobo sauce.
Add 1 tablespoon chili powder (I used New Mexican).
You can optionally add dashes of cumin, oregano and black pepper.
Add a couple of tablespoons of water and simmer over medium heat. By the time you gather all the taco fixings, the meat will be ready.
For the taco shells, start by warming up corn tortillas in the oven or microwave. Lightly brush with a neutral oil or cooking spray and drape over two oven rungs for 10-12 minutes at 375ºF.
Serve with diced tomatoes, chopped lettuce, shredded cheese and guacamole (optional).
Most taco seasoning packets are heavy on the cumin and oregano. I tend to shy away from using too much of these to avoid Tex-Mex overload. As photographed I added a dash of cumin and black pepper, but no oregano.
I usually pull the taco shells out of the oven before they are fully browned. This will leave them still slightly pliable.