Gyudon

Modified from:
https://www.justonecookbook.com/how-to-make-dashi/
https://www.justonecookbook.com/yoshinoya-beef-bowl-gyudon/

Ingredients for 1 cup of Awase Dashi

• 1/9 oz / 3.3g of kombu (4/3" x 4/3")
• 1/9 oz / 3.3g / 1/3 cup, dried bonito flakes
• 4/3 cup water

Procedure for Awase Dashi

• Gently rinse kombu and cut slits to release flavor.
• Combine kombu and water in a small pot.
• Slowly bring to a boil in medium-low heat.
• Just before dashi starts boiling, remove kombu.
• Add bonito and bring to a boil. Reduce heat and simmer for 30 seconds. 
• Turn off heat and let bonito soak for 10 minutes.
• Strain dashi.

Ingredients for Dish (2-3 servings)

• 1 onion
• 1-2 green onion/scallion
• 1 cup dashi
• 2 Tbsp sake
• 4 Tbsp mirin
• 2 Tbsp sugar
• 4 Tbsp soy sauce
• 1 lb thinly sliced beef (shaved beef at Trader Joe's works very nicely)
• Pickled red ginger, optional

Procedure for Dish

• Thinly slice onion and green onion.
• Combine dashi, sake, mirin, sugar, and soy sauce.
• Pour sauce into large frying pan over medium high heat. 
• Cover and bring to a boil.
• Spread onions evenly in pan, cover, and cook until tender.
• Add beef, making sure the slices don't stick together. Big chunks don't soak up the sauce well and also require more time to cook, making it tough - it may make sense to lower the heat to allow time for manually separating all the pieces. Cook until no longer pink. 
• Add green onion.
• Serve over rice with pickled red ginger, if desired.