Cup of Yum
1. Gather all the ingredients. Bring a large pot of water to a boil.
2. Prepare a large jar or container that can fit your tomatoes. Combine all the ingredients for the marinade: ½ cup dashi (Japanese soup stock), 1 cup rice vinegar (unseasoned), 4 Tbsp sugar, 1 Tbsp soy sauce, and 2 tsp Diamond Crystal kosher salt.
3. Using a knife, score an X in the skin on the bottom of 2 tomatoes. Place them gently into the boiling water.
4. Blanch the tomatoes for 10–15 seconds, flipping them once halfway through. Transfer the tomatoes from the pot to a cutting board.
5. You can dunk them in cold water for 10 seconds to cool or leave them on the cutting board until they‘re cool enough to handle. Then, gently peel off the skin using your fingers. Discard the skin.
6. Place the tomatoes in the marinade. Cover and keep in the refrigerator for at least 3 hours until completely chilled or up to 3–5 days.

To Serve

1. When you‘re ready to serve, mince ½ onion (optional) for garnish. You will need 2–3 Tbsp minced onion per tomato.
2. Soak the minced onion in a bowl of water to remove the bitterness. Squeeze out the water and they are ready to use.
3. Cut the tomatoes into ½-inch (1.3-cm) slices. Garnish with the minced onion and parsley (optional).