Pat the tofu dry with kitchen paper. Cut it in half lengthways, then slice into 1cm thick pieces. Arrange the slices on a plate lined with kitchen paper. Cover with another sheet of paper and place a second plate on top to weigh it down. Set aside to drain.
In a small bowl, add the tamari, mirin, gochujang, garlic, sesame seeds, most of the shallots(reserving some for garnish) and water, and stir to combine.
Heat the coconut oil in a non-stick fry pan over medium-high heat. Add the tofu slices and sauté for 4-5 minutes on each side, or until golden brown.
Pour the sauce mixture over the sautéed tofu in the fry pan. Scatter the green beans around the tofu. Bring the mixture to a simmer and cook for 10 minutes over medium heat, or until the sauce has thickened and the green beans are tender.
Sprinkle the reserved shallots over the dish. Squeeze lime juice over the top to taste and season with additional salt if needed. Serve hot alongside the cooked brown rice.