1Heat the broiler to high and arrange a rack in the top third of the oven. Cover a baking sheet with foil; set aside.
2Whisk the soy sauce, vegetable oil, and a pinch of pepper in a medium shallow bowl to combine. Dip the carrots and tofu pieces into the soy sauce mixture to coat (let the excess sauce drip off and back into the bowl), then lay the pieces on the baking sheet so they are not touching. Set the remaining sauce aside.
3Broil the carrots and tofu until browned on all sides, about 20 minutes total, turning the tofu every 5 minutes to brown on four sides and flipping the carrots after 10 minutes. Remove from the oven.
4Add the green onion, rice vinegar, and sesame oil to the reserved sauce and stir to combine. Add the broiled carrots and tofu to the sauce and toss to coat. Serve with steamed rice.