Stir barley into the water and return to a boil; reduce heat to medium low, cover, and simmer until the moisture is completely absorbed, about 45 minutes.
Remove from heat, fluff with a fork, and set aside.
Heat 2 tablespoons olive oil in a large skillet over medium heat; cook the garlic, about 1/4 of the white part of the green onion, and a pinch of salt in the hot oil until the onion begins to turn glassy, 1 to 2 minutes.
Stir the tofu into the onion and garlic; continue cooking and stirring another 4 to 5 minutes.
Remove the tofu from the skillet to a bowl and set aside.
Pour 2 tablespoons olive oil into the skillet; when the oil is again hot, cook the remaining white part of the green onion in the hot oil with a pinch of sea salt until they are soft and translucent.
Stir the yogurt, green onion, oregano, and flour together in a small bowl and add to the skillet along with the cooked barley; mix thoroughly and cook until the mixture begins to bubble.
Fold the tofu into the mixture; continue cooking until thoroughly reheated, 1 to 2 minutes.