Set your oven for 2-rack cooking. Preheat oven to 400F. Line both pans with parchment paper. Slick the parchment papers with olive oil.
Lay 2 sheets of paper towel on counter. Place tofu block on paper towel. Place 2 more paper towels on top of tofu. Lay a large cutting board on top. Place some heavy items on the cutting board to put weight on the board. Let sit at least 15 minutes.
Cut the vegetables according to their density: dense vegetables (like carrots, potatoes, parsnip should be cut in 3/4" cubes), medium vegetables (like cauliflower) just a little larger. Cut broccoli just a little larger than the cauliflower. Thin vegetables (like onion, bell peppers) - cut into wedges. Toss the vegetables into the prepared salad dressing and lay the vegetables on one of the baking sheets.
Cut tofu into 3/4" cubes. In a large bowl, gently toss the tofu cubes with olive oil. Add in the cornstarch and garlic salt, and toss to coat evenly.
Place the tofu cubes in one layer on the other baking sheets. Go ahead and put that on the upper rack of the oven. Set timer for 30 minutes. While the tofu begins roasting, prepare the veggies.
Place the tofu on the upper rack and the vegetable son the lower rack.
Cook everything for 20 minutes. At the 20 minute mark, remove the vegetables and flip the tofu. Cook the tofu for an additional 5-10 minutes, or until it has reached your desired crispiness. It will get harder as it cools, so keep that in mind!
Season everything with salt and pepper to finish and serve over rice if you wish!