Heat the oil in a large (large!) heavy-bottomed skillet over medium-high heat.
Place the entire block of tofu in the middle of the pan, moving it around to ensure it's well covered in oil. Sear for about 5 minutes on each of the largest sides, until crisp and golden. Remove the tofu from the pan onto a plate lined with a paper towel.
Add the diced red onion to the same pan, adding a bit more oil if needed. Stir-fry until the onion is just translucent.
Add the carrot coins, cauliflower, and broccoli florets, continue to fry, stirring frequently (they call it stir-fry for a reason!) for 3-5 minutes.
Add the diced zucchini, sugar snap peas, and baby corn, and continue to stir-fry for another 5 minutes. At this point the vegetables should be brightly coloured, golden in some places, and cooked but still crisp.
In a small bowl whisk the red curry paste together with a few tablespoons of the coconut milk and the honey. Add the remaining coconut milk and whisk to combine well.
Cube the seared block of tofu, and toss it into the stir-fry with the vegetables.
Add the coconut sauce and stir well - be careful, your pan may be VERY full at this point - continuing to cook for another 2-3 minutes, until everything is heated through and the sauce is bubbling.
Season with a sprinkle of salt and a good squeeze of lime juice. Taste, and adjust the seasonings if necessary.
Serve hot, spooned over bowls of brown rice. Garnish with cilantro and chili slices.