Rinse and inspect lentils to ensure wholeness. Place in a medium pot with water. Bring to a boil, then lower to a simmer. Allow to simmer, with lid partially covering pot, for 15 minutes.
Meanwhile place olive oil in a medium pan over medium heat. Add onion and sauté for 3 to 4 minutes. Add garlic and sauté for another minute. Add taco seasoning and sauté for another minute. Add Ro-Tel and bring to a simmer.
After lentils are done add to tomato mixture and simmer for 10 minutes. Pulse with an immersion blender a few times (optional, I like the texture it gives). Add salt and pepper if needed. Use like you would taco meat on tacos, nachos or soup/casseroles.
Recipe by pretty plain janes at https://prettyplainjanes.com/2016/02/11/lentil-taco-meat/