Turn the broiler in your oven on high.

Melt the butter/oil in a medium-sized sauté pan over medium heat on the stove. Add the onions and cook for several minutes until they start to soften.

Add the beef and beans to the pan. Break it up with a spatula while the beef browns. Season the meat mixture with the chili powder, cumin, oregano, salt, and pepper.

Place tortillas on a large, ungreased baking sheet and sprinkle them with cheese. Put a few dashes of cumin on top of the cheese. Put them under the broiler for 2 – 3 minutes or until lightly brown.

While the beef and tortillas are cooking, spread the lettuce out over a large serving platter then top it with rows of tomatoes, cheese, and sour cream.

Add the cooked ground beef mixture in a row on the serving platter. When the tortillas are done and have cooled slightly, slice them (kitchen scissors or a pizza cutter work great for this) and add them to the platter as well.

Sprinkle entire dish with fresh cilantro leaves and some fresh-squeezed lime juice. Serve immediately and enjoy!