Step 1

Fill the large saucepan with cold water about three-quarters full. Bring to a boil over medium-high heat. Gently add 10 large eggs to the boiling water. Boil for 6 minutes 30 seconds for a runny yolk, or 8 minutes for soft-boiled eggs. Meanwhile, fill a large bowl halfway with ice and water to make an ice water bath.

Step 2

Transfer the eggs to the ice water bath and let sit until cooled, about 8 minutes. Remove from the ice water bath and peel. Place in a flat container that will fit the eggs snuggly in a single layer.

Step 3

Prepare the following, adding each to the same large bowl as you complete it: Finely dice 1/4 medium yellow onion (about 1/4 cup); thinly slice 3 medium scallions (about 1/2 cup), 1 medium serrano pepper (about 1 tablespoon), and 3 garlic cloves.

Step 4

Add 1 cup soy sauce or tamari, 1 cup water, 1/4 cup granulated sugar, 3 tablespoons mirin, 1 tablespoon toasted sesame oil, 1 tablespoon toasted sesame seeds, and 1 teaspoon hondashi. Whisk well to combine, then pour over the eggs.

Step 5

Thinly slice 1/2 medium lemon and place evenly over the eggs. Cover and refrigerate for at least 6 hours or up to overnight before serving. Serve over hot white rice with a little bit of marinade if desired.