Preheat the oven to 425 degrees F.
Brown the ground beef over medium high heat, contiuing to break up the meat as it cookes. Drain excess fat, keep the pan hot.
Meanwhile, stir the taco seasoning ingredients: chili powder, cumin, paprika, garlic powder, and sea salt. Pour on top of the meat, adding in apple cider vinegar and the can of tomatoes. Give the mixture a quick stir.
Now stir in the lentils and broth. Increase the heat to high, or until the mixture comes to a rolling boil. Reduce the heat to low and a gentle simmer. Let the lentils soak up the moisture and cook for about 12-15 minutes. Add salt to taste if needed, then remove from heat.
Assemble the tacos by filling each tortilla with a scoop of the beef/lentil mixture, and a few tbsp of cheese. Fold the tacos in half and lightly brush oil on both sides of the exterior of the taco. Place on a lightly greased sheet pan, or sheet pan covered in parchment paper.
Bake until crispy, about 15 minutes, flipping when baking is halfway. The tacos are done when they are golden brown and crisp on both sides.
Let cool slightly before serving with your favorite taco toppings.