These are not traditionally made tacos. Because I was using high-quality beef, I skipped the spices to let the flavor of the meat (fat) come through, and topped it with collard greens.
I thought the collard greens would add a richer flavor to complement the beef; I didn't think lettuce would stand up. I started the greens first because they take longer. I cut the stems out of the collards and rolled them up, cutting them into thin strips. After I had done that, I ran the knife through them the long way to make them shorter. I started some oil, added some garlic, and then the greens. The top went on the pot, and I put it on a low heat.
My general rule for good beef is "don't ruin it". Doing anything to it is a form of ruining it, so I make it as simple as possible. I only added salt, pepper, some very nice sun dried tomatoes, and homemade pickled jalapenos. The tomatoes and jalapenos went in a little grape-seed oil, followed by the ground beef, which I had taken out of the refrigerator when I first got into the kitchen. I pulled apart the meat by hand as I dropped it in.
I cooked it until it was only a little pink and turned off the heat. The heat already in the pan and fat continue to cook the beef, so I stopped a short of where I wanted to end up. I let that sit while I finished up the greens with a dash of herbed vinegar a friend had given me.
Finally, everything went into the taco shell, which I had toasted crisp in the oven. The tastes and textures came together really well, and I think this an example of getting good ingredients and staying out of their way, although that is something that gets harder and harder to do as the winter comes.