Cut tofu planks into 2 x 1 inch pieces. Arrange on paper towel lined plate. Let drain 15 minutes.
Whisk together chili sauce, soy sauce, ginger and 1/2 t. cornstarch in bowl.
Heat 1 T. oil in large nonstick skillet over medium-high heat until just smoking. Add bok choy stems and cook until just tender, about 3 minutes. Add greens and cook until wilted, about 2 minutes. Drain in colander.
Add rest of oil and garlic to skillet. Cook until garlic is golden, about 2 minutes. Use slotted spoon to transfer garlic to paper towel-lined plate.
Spread rest of cornstarch in shallow plate. Pat tofu dry. Season with salt and pepper. Dredge in cornstarch, shaking off excess. Cook tofu in garlic oil, turning occasionally, until golden, about 8 minutes. Pour off oil from skillet. Add chili sauce mixture and drained bok choy. Toss to combine. Top with garlic chips.