Pour boiling water over the dried mushrooms and let them soak for about 10 minutes. Afterwards, drain them and squeeze out any excess water. Then, slice them.
Peel the carrots and cut them into thin sticks. Dice the tofu.
Mix the miso paste with salt and oil. Split the mixture evenly between the jars.
Now layer the peas, noodles, mushrooms, carrots, and tofu in the jars.
Pour boiling water over the ingredients and let the soup steep for 5 minutes.
Stir the instant noodle soup in the jar and sprinkle with chopped scallions, if desired before serving.