Heat the oven to 425. Line a rimmed metal baking sheet with parchment paper then toss the sweet potatoes in olive oil until evenly coated. Roast for 20 to 25 minutes until tender, flipping halfway through.
When the sweet potatoes have about 10 minutes left to cook, bring the vegetable broth to a low boil in a small pot. Slowly stir in the polenta then gently simmer for 5 minutes, stirring occasionally. Stir in the nutritional yeast, red pepper flakes, black pepper, and salt to taste. Cover and let sit for 2 minutes.
While bringing the broth to a boil, heat 1 tablespoon of olive oil in a medium-large nonstick skillet over medium heat. Add the tofu to one side of the pan and the broccoli to the other. Cook until the tofu is hot and the broccoli is crisp-tender, flipping as needed. Lower the heat then pour the BBQ sauce over the tofu, folding for one minute until hot.
Spoon the cooked polenta into a bowl, then top with the BBQ tofu, broccoli, roasted sweet potato, and avocado. Season with salt and pepper.
