In a small bowl, whisk together the miso paste, soy sauce, and ¼ cup water. Heat remaining 1 teaspoon coconut oil in the same skillet or wok over medium-high heat. Add garlic and cook, stirring, until fragrant, about 30 seconds. Add brussels sprouts and miso mixture and toss to combine. Cover skillet and cook until brussels sprouts are bright green, about 2 minutes. Add carrots, tofu and cook, stirring frequently, until sauce coats the vegetables. Add sesame oil and toss to combine. season to taste with salt and pepper. Serve with farro and sriracha if desired.