In a medium saucepan, combine the rinsed lentils, vegetable broth (or water), tomato sauce, and 1 teaspoon of kosher salt. Bring to a boil over medium-high heat. Once boiling, reduce heat to low, cover, and let simmer for about 20-25 minutes, or until lentils are tender. Stir occasionally to prevent sticking.
After the lentils are cooked, stir in the taco seasoning, mixing well to ensure the lentils are evenly coated. Allow them to simmer for an additional 5 minutes.
While the lentils are simmering, prepare your toppings. Shred the cabbage, chop the tomatoes, onions, and cilantro, and slice the avocado. Squeeze half of the lime over the avocado to prevent browning.
In a dry skillet over medium heat, warm the flour tortillas for about 30 seconds on each side, or until pliable and slightly toasted.
To assemble the tacos, spoon a generous amount of the lentil mixture onto each tortilla. Top with shredded cabbage, diced tomatoes, onions, cilantro, and avocado slices. Finish with a squeeze of lime juice and any additional toppings you desire.
