Add the water, stock, and salt to a large pot and put on high heat and add the potatoes. Bring to a boil and reduce to a high simmer for 10 minutes. Then add the carrots and reduce to a simmer for another 10 minutes.
While the potatoes and carrots are cooking, heat a large pan with a splash of olive oil and saute the onion and celery until softened and starting to brown, then add this to the pot.
Add the shrimp to the pot. I used small White shrimp from a local farm, you can use any type of shrimp or prawn you like. I measured the weight after the head, shell, and tails were removed.
Add the fish to the pot. I used 3 Pangasius (Shark Catfish) fillets, you can use any whitefish you like, Tilapia and Sea Perch (Barramundi) would also work well, keep in mind, boneless and skinless.
Add the bay leaves, Mrs. Dash seasoning, parsley, pepper, and if using the optional Straw mushrooms, just slice those in half lengthwise and add those to the pot as well.
Cook on a high simmer for about 10-15 minutes to cook the mushrooms, important, skim off any foam on the surface to give a clear broth. Taste and season with additional salt if needed, serve.