I recently fell in love with Udon soup. I've had it at 2 different restaurants in Austin TX, and I find the broth clean and delicious. My favorite includes cucumber, carrot, a few shrimp, green onion, a and lil of tempura bits. Usually I love spicy soups, but the broth tastes so well balanced that i wouldn't really dare adding any chili, etc. I have tried to recreate it at home but the broth is not remotely similar.
I've tried making dashi broth a couple times. The second time was after a lot of internet research. I added about 4 2"x4" strips of Kombu to bout 5 cups water cold water, and brought it to near-boil over 30 minutes. I tasted and really noticed the umami flavor. But still, it tasted quite watery. I added 2 handfuls of bonito flakes (they reached boil for maybe a second) and removed from heat. Steeped 10 minutes. I could taste more fishyness now. I slowly started adding salt and it really started bringing out the fishyness, too much. I added soy a little at a time.. maybe a tablespoon all told and it was quite 'soy' tasting. not really the golden-rays-of-sunshine broth i had at the restaurant. I added a bit of mirin, maybe a tablespoon. At this point the stock tastes discordant: too fishy, too soy-like, and too salty, too sweet, and too watery.
Am I messing something up, or are these restaurants using some kind of chicken stock? I feel like I'm not in the ballpark. fwiw, I'm using light soy and sushi-chef mirin.
Any guidance/suggestions will be greatly appreciated!
UPDATE: I wrote the restaurant asking what was in the broth, and if they used dashi. Here is there response: "Our soup broth is made with chicken bone, beef marrow, and assortment of vegetables that is simmered for several hours"