Whisk garlic, harissa, 1/4 cup plus 2 Tbsp. oil, and 3 Tbsp. vinegar in a large bowl; generously season with salt and pepper. Toss broccoli and tofu in harissa mixture until coated. Season with salt and pepper. Transfer broccoli mixture to a lined baking tray, spread out evenly, and roast, turning everything halfway through, until broccoli is lightly browned and cooked through, 30–40 minutes.