We had daikon, firm tofu, and chayote squash on hand, so we tried this plant-forward recipe: https://web.archive.org/web/20240521065002/https://viceatsworld.com/vietnamese-canh-bau-opo-squash-soup/. Its flavors are surprisingly complex and delicious, and the soup comes together very quickly. It makes a great weeknight meal.
Our modifications: first, we often use chayote squash in lieu of opo squash (aka bottle gourd). They are both thin-skinned squash with mildly sweet flesh, but chayote is more consistently juicy (whereas opo squash can get spongy as it ages).
Second, we generally prefer brothier soups. So instead of 5 cups water, we used 6 cups chicken broth (4 cups unsalted chicken broth plus 2 cups Better Than Bouillon chicken broth). However, because the 2 cups of seasoned chicken broth had some salt, we kept the fish sauce and its original amount (3 Tbsp). (See Note below.)
Third, for the vegetables we used 1 small-medium, slender daikon, 2 large chayote, peeled and then sliced into 1/2″ thick, 1×2″ rectangles. We used 8 oz firm tofu, rinsed, dried, and cut into 1″ dice. After bringing to a boil, we reduced to medium-high heat (6.5 on our range) for 12 mins uncovered, then reduced to a simmer (3 on our range), covered for 5 mins.
Finally, instead of garnishing with white pepper, we added 1/8 tsp of white pepper to the soup before we brought it to a boil. (We wanted to incorporate its flavors while cooking). We concurrently seasoned with 1/2 tsp freshly ground black pepper. We served this with freshly cooked jasmine rice. (Dec. 2022)
Note: Even after increasing the liquid from 5 cups to 6 cups, we still found the soup almost too chunky. We may increase to 7 cups broth, in which case we likely would slightly increase the fish sauce from 3 Tbsp to 3 Tbsp plus 1 tsp.
Cooking Adventures 