Cut rhubarb into 1/2-inch thick slices and quarter the strawberries into roughly 1-inch pieces. Split the vanilla bean lengthwise and scrape out the seeds with the back of a knife—you'll use both the seeds and the pod for maximum vanilla flavor. Measure out the water, sugar, salt, and lemon zest and set everything nearby so you're ready to work efficiently once the cooking begins.

In a medium saucepan, combine water, sugar, salt, and the vanilla bean (seeds and pod). Simmer over medium heat for 2-3 minutes, stirring occasionally, until the sugar completely dissolves and the mixture turns clear. This creates a light syrup that will cook the fruit gently and infuse it with vanilla flavor throughout.

Add the sliced rhubarb to the simmering syrup and cook for about 5 minutes over medium heat, stirring occasionally, until the rhubarb begins to soften and break down slightly. I like to let the rhubarb cook just until it loses its raw texture but still holds some shape—this gives the compote a better consistency with actual fruit pieces rather than a completely smooth puree.

Remove the pan from heat completely, then immediately stir in the prepared strawberries and lemon zest. The residual heat will gently soften the strawberries in just 1-2 minutes while keeping them from overcooking and becoming mushy. Once the strawberries are warmed through and slightly softened, remove and discard the vanilla bean pod (the seeds remain mixed throughout).

Transfer the compote to a serving bowl and let it cool for 10-15 minutes at room temperature, or refrigerate it for several hours if you prefer to serve it cold. I find that strawberry rhubarb compote actually tastes better after sitting for a little while—the flavors meld together beautifully. Serve as desired over yogurt, ice cream, cake, or on its own.