You are going to macerate the grapefruit and kumquats for several hours or overnight before serving this. Macerating is a technique where fruit is combined with some kind of sugar, which creates a syrup as it draws liquid out of the fruit. In the case of grapefruit and kumquats, it sweetens them enough to balance the flavors. My mom always did this with summer berries, sprinkling sugar over them in a bowl in the fridge. I'm sure she had no idea it had a fancy term like macerating. Go Mom!

Whisk the agave syrup or honey together with the vinegar in a bowl large enough to hold the salad.

Start by cutting off each end of the grapefruit, then slicing off all the peel, using a serrated knife. You should always use a serrated knife on citrus peel, as cutting it can dull regular knives. You should now have a naked grapefruit with very little white pith left.

Switching to a sharp paring knife, cut each individual section of grapefruit into the bowl with the syrup-vinegar mixture, leaving the pith in between each segment. When you have cut all the segments into the bowl, squeeze all the juice out of what remains. You have made "supremes." Not to be confused with the Motown group.

Slice the kumquats as thinly as possible and add them to the bowl.

Toss the fruit with the syrup, then cover and refrigerate for several hours or overnight.

Just before serving, cut each avocado in half lengthwise, then twist the halves apart. Using a sharp paring knife, score the avocado in both directions (cutting just to the peel but not through it), then use a grapefruit spoon to scoop out the square sections into the bowl with the grapefruit.

Finely chop the mint and add to the bowl. Toss. Add a small amount of salt if you like.