Heat a large skillet over medium heat. Add the ground beef and break it apart with a wooden spoon as it cooks. Brown for about 7-8 minutes until no pink remains.
While the beef is cooking, prepare all your fresh ingredients. Wash and chop the lettuce, dice the tomatoes and red onion, and set aside.
Once the beef is browned, drain excess fat if necessary (leave a little for flavor).
Return the skillet to medium heat and sprinkle the taco seasoning over the beef. Add approximately 1/4 cup of water, stirring to combine. Simmer for 2-3 minutes until the water reduces and the seasoning coats the meat evenly.
Transfer the seasoned beef to a large bowl and allow it to cool for about 5-10 minutes.
While the meat is cooling, gently crush the Doritos into bite-sized pieces. Don't pulverize them – you want chunks large enough to provide that signature crunch.
Add the crushed Doritos to the bowl with the beef. If serving immediately, proceed to the next step. If preparing for later, keep the Doritos separate until just before serving.
Add the shredded lettuce, diced tomatoes, red onion, black beans (if using), corn (if using), and other optional ingredients like olives or jalapeños.
Sprinkle the shredded cheddar cheese over the mixture.
Dollop the sour cream on top or mix it in gently, depending on your preference.
Garnish with fresh cilantro leaves and serve immediately while the Doritos are still crunchy.
