Slice tofu lengthwise into 4 rectangular pieces, then slice the rectangles in half to make 8 pieces.

Marinate the tofu in teriyaki for 20 minutes to infuse with flavor.

Mix arrowroot or cornstarch with sesame seeds in a shallow bowl or plate.

Press marinated tofu into the sesame seed mixture to evenly coat all sides.

Heat sesame oil in a large skillet on medium heat, add tofu squares in a single layer to cook for 5 minutes on each side. Add soy sauce and cook for one more minute until liquid is absorbed. Transfer tofu to separate plate.

In the same pan (no need to clean), add olive oil and garlic and saute for 30 seconds until golden. Add spinach and cook until wilted. Add a teaspoon of water if needed. Season with salt and pepper.

Serve tofu on a bed of wilted spinach and brown rice (optional).