Step 1: Cook the sago pearls. Bring 4 cups of water to a rolling boil in a medium saucepan. Add the sago pearls, stirring occasionally to prevent sticking. Cook for 15-20 minutes, or until most of the pearls are translucent with only a tiny white dot in the center. Pro Tip: Don't overcook or undercook. They should be chewy, not mushy or hard.
Step 2: Let the sago rest and rinse. Turn off the heat, cover the saucepan, and let the sago sit for another 5-10 minutes until completely translucent. Drain the sago through a fine-mesh sieve and rinse thoroughly under cold running water until the pearls are no longer sticky and are completely cooled. This stops the cooking process and removes excess starch. Set aside.
Step 3: Prepare the strawberry puree. In a blender, combine 2 cups of hulled and quartered fresh strawberries with 1/4 cup granulated sugar and a pinch of salt. Blend until smooth. Taste and adjust sugar if needed; for extra texture, you can reserve a few small diced strawberries to mix into the puree or milk.
Step 4: Mix the strawberry milk base. In a large bowl, combine the strawberry puree, 1.5 cups whole milk, and 1/2 cup sweetened condensed milk. Whisk until well combined and smooth. Taste and adjust sweetness to your preference. This mixture forms the delightful base of your Korean Strawberry Milk Sago Dessert Cups.
Step 5: Assemble the dessert cups. Divide the cooked and rinsed sago pearls evenly among 4 individual dessert cups or jars. Pour the strawberry milk mixture over the sago. Pro Tip: Gently stir the sago into the milk mixture in each cup to distribute the pearls evenly.
Step 6: Garnish and chill. Top each cup with fresh diced strawberries. For an extra touch, you can add a few whole strawberry halves. Cover the cups and refrigerate for at least 2 hours, or preferably longer, to allow the flavors to meld and the dessert to chill thoroughly. These Korean Strawberry Milk Sago Dessert Cups are best served cold.