Drain and press the block of tofu for at least 30 minutes prior to marinading the tofu. Press out as much water as possible. Cut into 1/2-inch cubes.
To make marinade, in a small bowl, whisk together all ingredients except for the vegetable blend.
Place tofu in a large container or plate so the tofu can lay in one layer, not stacked on top of each other. Pour marinade over the tofu so it's covering it completely. Let tofu sit for at least an hour so the flavors can soak in. You can even make this in the morning or the evening before so the flavors can really get in there.
To cook the tofu, pour it into a large nonstick pan over medium high heat and let brown on one side, for about 7-10 minutes. Press out the liquid with the back of a spatula while browning the tofu. Once it's browned on one side, flip over to brown the other side.
While the tofu is browning, steam the Southwest Style vegetables per the instructions on the package.
When ready to serve, top vegetable blend with tofu cubes.