• Gather all the ingredients. Keep the bacon in the refrigerator or freezer so it‘ll be easier to cut.
  

To Make the Dashi

• To a medium saucepan, add 4 cups water and 2 dashi packets. Cover the saucepan with a lid and bring it to a boil on medium heat.
  
• Once the water is boiling, shake the dashi packets with cooking chopsticks to release more flavor. Reduce the heat to medium low and cook, covered, for 2–3 minutes.
  
• Discard the packets. Then, transfer the dashi to a measuring cup or another container. Set aside the saucepan, as we‘ll be using it to cook the miso soup.
  

To Prepare the Ingredients

• Peel 1 russet potato and remove any sprouted eyes. Slice it crosswise into 1-inch (2.5-cm) rounds.
  
• Cut the rounds into quarters. Then, soak them in water to remove the starch.
  
• Meanwhile, prepare 6 asparagus spears. Trim off the woody ends, then peel the bottom 2 inches (5 cm) of the stems with a vegetable peeler to remove the tough outer layer.
  
• Slice the asparagus diagonally into pieces ½ inch (1.3 cm) wide.
  
• Remove 3 slices bacon from the refrigerator. Cut crosswise into ½-inch (1.3-cm) pieces.
  

To Cook the Miso Soup

• Heat the same medium saucepan on medium heat. When it‘s hot, add the bacon and cook, stirring occasionally.
  
• When the bacon‘s edges are slightly charred, wipe off the rendered fat from the saucepan with a paper towel. The bacon will continue to release more fat as it cooks, so don‘t worry about losing bacon flavor.
  
• Drain the potatoes, then add them to the saucepan. Toss to coat them with the bacon fat.
  
• Add the dashi and cover the saucepan with the lid. Gently boil the potatoes until 80% cooked (this took me 10 minutes). Do not overcook the potatoes at this stage, as they will continue to cook with the asparagus in the next steps.
  
• Insert a skewer into a piece of potato to test it. When it doesn‘t go through quite yet but is getting close, add the asparagus.
  
• Cover and simmer to cook for 4–5 minutes. The cooking time will vary depending on the asparagus thickness. When both the asparagus and potatoes are perfectly tender, turn off the heat.
  

To Add the Miso

• Put 4 Tbsp miso in a ladle, add some hot stock to the ladle, and stir with chopsticks to dissolve completely, then add to the soup. Alternatively, you can use a fine-mesh miso strainer and/or a miso muddler to dissolve it faster. Now, taste the soup and add more miso if needed. If it‘s too salty, dilute with more water or dashi (if you have any).
  

To Serve

• Serve the miso soup in individual bowls and top each bowl with a thin slice of unsalted butter. I also recommend mixing in some shichimi togarashi and yuzu kosho!
  

To Store

• It‘s best to consume all the miso soup right away because it loses aroma and taste over time. If you‘d like to keep leftovers, cool the soup to room temperature (no longer than 4 hours), store in an airtight container, and keep for up to 2 days in the refrigerator or 2 weeks in the freezer. When ready to use, reheat in a pot over medium heat until it‘s just hot; do not boil.