Stir the olive oil, lemon juice, garlic, rosemary, lemon zest, ½ teaspoon of salt, and ½ teaspoon of black pepper together in a shallow dish.
Cut the tofu into about eight slabs, about ½ thick each, then cut each slab in half to make two squares. Cut each square in half diagonally to create triangles. You should end up with thirty two triangles (Note 1).
Place the tofu into the dish with the olive oil mixture, and gently stir to coat the tofu in the dressing. Let the tofu marinade for about 30 minutes (Notes 2 and 3).
Preheat the oven to 400°F.
Arrange the tofu triangles in a single layer on a 10 x 15 inch (or larger) baking sheet, reserving any excess marinade in the dish. I like to confine them to one area of the baking sheet so there's room for the potatoes, which you'll add later. Place the baking sheet into the oven and set the timer for 15 minutes.
While the tofu bakes, cut the potatoes into bite sized pieces. Typical yellow potatoes can be quartered, but larger ones may need to be cut into more pieces, and very small ones can be halved or even left whole. Place the potatoes into the dish with the marinade and gently toss to coat them in the marinade.
Once the timer goes off, remove the baking sheet from the oven. Arrange the potatoes in a single layer in the empty space on the baking sheet, reserving any leftover marinade in the dish. Place the baking sheet back into the oven and set the timer for five minutes.
When the timer goes off, remove the baking sheet from the oven again, then place the broccoli and pepper on the baking sheet. Drizzle them with any remaining marinade. You can stir everything up at this point, but try to get the ingredients in as even a layer as you can.
Place the baking sheet back into the oven and roast everything for 20 minutes more, or until the vegetables are tender and lightly browned, the potatoes are easily pierced with a fork, and the tofu pieces have shrunken and darkened slightlly.
Remove the baking sheet from the oven and sprinkle everything with additional salt to taste (I use about another ½ teaspoon).
Divide onto plates and serve.