Heat the olive oil in a medium, heavy-bottomed pot over medium heat. Add the diced onion, pepper and celery. Cook, stirring occasionally for about 5 minutes, or until they soften. Sprinkle in the cumin and chili powder; cook for an additional minute.
Add the lentils, 3 cups of water, tomato sauce, tomato paste, Sriracha and salt. Increase heat to medium and bring the lentils a simmer. Cook uncovered for about 30 minutes, stirring occasionally. Add more water if the level falls below the lentils.
Taste the lentils, and if they are sufficiently tender (stoves and pots may vary) adjust the salt and add the balsamic. Stir and serve over buttered buns you favorite toppings.