I suppose one could argue that this isn’t truly a one-pot meal, since you have to steam the potatoes and green beans first. But I still fondly think of it that way since the recipe essentially comes together in one large skillet where you dump everything and stir.
Another technique you might try for crumbling the tofu is to “shred” it with a fork. Place the block of tofu on a plate. With the fork right side up (curved side down) drag the tines of the fork down the face of the tofu block, starting at the top and ending with the fork touching the plate. Repeat this until you have a plate mounded full of tiny tofu shreds.