Press tofu for anywhere from 15-45 minutes. If you don't have a tofu press, wrap tofu in paper towels, place on a plate, put another plate (or heavy skillet) on top, and add weights (cans, books, other pots and pans). Cut into 1-inch cubes and pat dry.
Heat oven to 400°F and line a large sheet pan with parchment paper.
In a large bowl, whisk together olive oil, miso, lemon juice, cornstarch, salt, pepper, and any optional seasonings until smooth.
Add tofu and broccoli to the bowl. Toss gently until everything is evenly coated.
Spread everything out in a single layer (use two pans if needed— crowding leads to soggy tofu). Roast for 18–20 minutes, flipping once halfway, until tofu is golden and crisp and broccoli has charred edges.
Sprinkle with lemon zest, sesame seeds, and an extra squeeze of lemon juice. Taste. Adjust. Eat immediately.