Drain the tofu, put into a press (or wrap in towels and place under your heaviest books) for at least 10 minutes. Once most of the water is drained, cut the tofu into approximately 1" squares and set aside.
Meanwhile, clean and chop the veggies into approximately 1/4" slices. Clean and loosely chop the mushrooms. Slice the green onions and set aside.
Heat a large saute pan and add a bit of sesame oil. Add the veggies (hold on the mushrooms for a sec and do not add the green onions) and saute for about 10 minutes, until they start to soften and darken.
Add the mushrooms and saute for 15 more minutes, stirring often, until the veggies and mushrooms are browned.
Meanwhile, heat another large saute pan and add about a tablespoon of sesame oil. Top the pan with the tofu, turning it immediately so both sides are covered with oil. Then sprinkle with salt, pepper, and garlic powder.
Saute the tofu for 5 minutes, then turn and cook a final 3-4 minutes, until both sides are browned.
Make your cauliflower rice according to package directions. This typically takes about 5-7 minutes to heat up, so it's good to do this as the last step.
Now, plate your food! In large bowls, layer the cauliflower rice, then the veggie mixture, then the tofu, and top with peanut sauce and your green onions.
Enjoy immediately!