Trim the ends and leaves from the stalks and discard. Cut the rhubarb into 6-inch lengths and place in a shallow pan, bowl or dish. Fill with cold water and soak the rhubarb for about 20 minutes.

Drain the rhubarb and dry with paper towels. Cut the rhubarb crosswise into 1/4-inch pieces or chunks. Set aside.

Pour the orange juice, sugar and salt in a medium nonreactive saucepan. Bring to a boil over medium-high heat.

Add the rhubarb to the pan and return to a boil. Reduce the heat to medium-low and simmer, stirring once or twice, until the rhubarb is tender but not mushy, about 8 to 10 minutes.

Once the rhubarb has cooked down and transformed into a sauce-like consistency, remove from the heat. Stir in vanilla, if using. At this point you can cool the sauce and serve as is or for a smoother texture use an immersion blender and blitz to the desired consistency. If you prefer a chunkier sauce like the one pictured above, simply leave the mixture as is.

Allow the sauce to cool completely before transferring to a jar or airtight container. Store in the refrigerator for up to two weeks. The flavors will develop over time, making it even more delicious.