Bluefish is a favorite in our house. It combines full flavor with more delicacy than it is given credit for, and it is fished in our Long Island waters. Jackie and I had our first of 2018 on the eve of the summer solstice, at a moment when our local farmers’ market also yielded abundant beets and no-longer-quite-so-abundant rhubarb. Since tart or sweet-tart accompaniments are a fine thing with tolerably fatty fishes, I wondered whether the sweetness of the beets and the tartness of the rhubarb would do the job without the use of sugar or vinegar/citrus.I wondered too whether I’d be able to attain the texture I was imagining: rhubarb that hadn’t collapsed into a mush, and beets that retained some crunch but were tender enough to make a nice mouthful with the juicy fish. Of the latter I was confident: Years ago I learned that cut-up beets can be sautéed without prior roasting or steaming, and since then I’ve repeatedly used them, jazzed up with vinegar, alongside fish. The open question was the 3/8-inch dice of rhubarb, and a test run in a greased frying pan yielded the pleasantly surprising outcome that just over a minute on the fire would give me the crunchy but cooked rhubarb I was looking for.A few other ingredients would be needed to round out the flavor: dill because of its Eastern European association with beets; mint as an herb that is marvelous with stronger-flavored fish; and fresh ginger for its own flavor and for heat to balance the sweetness and tartness. It worked as well as I’d hoped, and, although it was devised for fish, the beet-rhubarb mixture would be delicious with grilled or roasted chicken too.The sauce/accompaniment should be prepared just before you cook the fish: if it sits around, the rhubarb will turn mushy in texture, though the flavor will be fine.