If you don’t have day-old rice, cook 1 cup dried rice as far in advance as possible and refrigerate until cool and dry. If you’re really pressed for time, spread it on a baking sheet and place it in the freezer until cool.
Place the cubed tofu in a container and sprinkle over 2 tablespoons of cornstarch. Close the lid and shake to coat the tofu in cornstarch. Add more cornstarch as necessary to get an even coat.
Heat 1 ½ tablespoons of the oil in a wok or large pan over medium-high heat. Fry the tofu, flipping as necessary until each side is golden and crispy. Remove to a plate.
Add another 1 ½ tablespoons of oil to the pan and fry the onion until translucent. Add the carrots and fry until tender.
Make a space in the centre of the pan and add the ginger and garlic. Fry until soft and fragrant.
Add the rice, frozen peas and fried tofu. Mix everything together then let the rice sit of a few minutes to brown and crisp a bit. Toss it and let it sit again. Keep doing this until everything is heated through and the rice has some crispy bits.
Add the soy sauce and sesame oil and toss. Remove the pan from the heat and add the chopped kimchi and its juice. Taste and add a pinch of salt if necessary to bring all the flavours together.