Heat oil in a large nonstick pan or wok over medium-high heat. Add tofu to pan and cook, browning on most sides, about 6-8 minutes. Reserve the marinade.
If you prefer to grill the tofu, prepare a medium-hot grill. Brush the grill with oil, and grill until grill marks appear, 1 1/2 to 2 minutes per side. Reserve.
For the veggies: Heat oil in a pan, add garlic and sliced bell pepper or blanched veggies and cook for half a minute. Add the sauce you marinated the tofu in, and cook until sauce begins to bubble (2-4 minutes). Then reduce heat, cover and cook for another 2 minutes or until the veggies are cooked but crispy.
Serve with buckwheat noodles. Provecho!