Heat the oven to 400°F (200°C). Rub the whole scrubbed carrots with the olive oil and salt, wrap them together loosely in foil, and roast directly on the oven rack until completely tender when pierced with a knife, 30 to 40 minutes depending on thickness. Unwrap and let them cool until you can handle them.

Using a vegetable peeler, shave the cooled carrots lengthwise into long thin ribbons. Discard the woody core ends if they resist the peeler, and don't worry if a few ribbons tear, shorter pieces cure just as well.

Whisk the soy sauce, rice vinegar, maple syrup, liquid smoke, and olive oil in a shallow dish. Add the carrot ribbons, the torn nori pieces, and the cracked pepper, and turn everything gently so every ribbon is coated. Cover and refrigerate for at least 4 hours or overnight, turning once or twice if you think of it.

Lift the ribbons out of the marinade with a fork, letting the excess drip off, and pick out and discard the nori pieces. Serve on bagels with vegan cream cheese, capers, and dill. Keep any leftovers in the marinade in a sealed jar in the fridge.