Remove the peel and the pith from the oranges and grapefruits with a sharp knife, including some of the outer skin. Cut between each segment on either side to remove the segments (also known as “supremes”) from the membranes. Once all the segments have been removed from the fruit, squeeze the remaining part of the fruit over a bowl, to extract any leftover juice that may remain.

Meanwhile, dissolve the sugar in boiling water. Cool to lukewarm. Place strawberries in a bowl with dissolved sugar and let rest for 10 minutes.

Combine all ingredients and stir together. Cover and refrigerate.

Right before serving, grate some lime rind into the bowl to add flavor and color. Serve chilled.