To supreme citrus fruit is just a fancy way of saying to segment the citrus. It’s a technique done to remove just the flesh of citrus segments, leaving behind the membrane. It makes for a wonderful addition to salads, or to create a garnish for a dish. I mainly use this technique for oranges and grapefruits, since I mainly just use the zest and juice of lemons and limes.
If you wish to use the zest in your dish too, zest the peel of your citrus fruit first and set the zest aside.
Now, cut the top and bottom off the fruit at the pole ends, cutting away the pith (white part) and the peel. This will help create a flat surface for the citrus to sit on.
Now, sit the citrus down on one of its flat poles and cut away the peel/pith from top to bottom, curving around the citrus. You will need to do this in sections, most likely 6-8 cuts. I always need to go back and trim extra pith away, especially towards the bottom of where I was cutting. You will loose fruit, but I save the rind with any flesh to squeeze into my salad dressing (or into a cup to drink).
You should now have a bare looking citrus fruit, with just flesh and membrane.
To remove the segments in full pieces use a sharp pairing knife. I like to hold the fruit over a bowl to collect the juice (again, to either drink or use in a dressing). Holding the fruit cut down one side of a segment between the flesh and the membrane. Cut as close as you can to the membrane. Then cut down the other side of the flesh close to the other side of the membrane. The segment is now loose from the membrane.
Repeat with each segment.
When all the segments are released I like to squeeze the remaining membrane over a bowl to collect all the juices.
Serve the membranes alone as is, add to salads, add to yogurt, top a dessert, or even add a segment to a beverage.