• Gather all the ingredients.
  

To Prepare the Vegetables and Chicken

• Cut 1 head broccoli into bite-sized florets.
  
• Cut ½ onion into 6 wedges.
  
• Peel 1 carrot and 1 Yukon gold potato.
  
• Cut the carrot into bite-sized chunks. I rotate the carrot a quarter turn between cuts. To learn this Japanese cutting technique, see How to Cut Rangiri.
  
• Cut the potato into 1½-inch chunks and soak them in a bowl of water until ready to use.
  
• Cut the stems off 4 cremini mushrooms and cut the caps into thin slices.
  
• Blanch the broccoli in boiling water for 3 minutes until barely tender and still crisp. Remove from the water and let cool. Tip: Don’t overcook the broccoli now as it will cook a bit more when we reheat it in the stew.
  
• Cut 1 boneless, skinless chicken thigh into into 1½-inch pieces of even thickness. I tilt the knife back and slice at a diagonal. The slanted surface gives each piece a flatter and more open area so the chicken cooks evenly and faster. To learn this Japanese cutting technique, see How to Cut Sogigiri. Next, season the chicken pieces with ¼ tsp Diamond Crystal kosher salt and freshly ground black pepper.
  

To Cook

• Preheat a pot over medium heat and add 1 Tbsp of oil. Add the onion to the hot oil and sauté for 2 minutes.
  
• Add the chicken to the pot and cook until no longer pink.
  
• Add the drained potato and carrot. Stir to coat with oil.
  
• Add the mushrooms and coat with oil. Then, add 2 cups water.
  
• Push the ingredients into the liquid to submerge them and cover the pot with a lid. Bring it to a boil, then reduce the heat to a simmer. Cook for 15 minutes or until the potato is tender. Meanwhile, skim off the scum and fat from the surface of the broth. Tip: Set a timer so you don't overcook the potato.
  

To Add the Roux

• Pierce a potato with a bamboo skewer to see if it goes in easily. If it does, turn off the heat and add 4 cubes Japanese Cream Stew Mix. Add 1–2 roux cubes to a ladleful of hot broth, mix it with chopsticks to dissolve completely, and stir it in to the stock. Repeat with the remaining roux cubes.
  
• Turn on the heat again and add ⅓ cup milk. Stir and cook for another 5 minutes.
  

To Serve

• Add the broccoli and let it warm through. Serve in individual shallow bowls and enjoy it with steamed rice in the bowl or crusty bread on the side.
  

To Store

• You can store the leftovers in an airtight container and keep it in the refrigerator for up to 2 days. If you plan to freeze it, remove the potatoes (their texture will change) and freeze for up to a month.