Cut grapefruits crosswise into 1/4-inch slices. Cut each of these in half and remove any seeds and white center membrane. Transfer to heat proof glass bowl.
In small saucepan, combine honey and 1/4 cup plus 2 tablespoon of water. tie coriander seeds and peppercorns in small piece of cheesecloth and add saucepan. Bring slowly to boil over moderate heat to make light syrup.
Pour the honey sauce over grapefruit. Let stand until cool then cover and refrigerate overnight, stirring once or twice. Serve chilled.
If grapefruit is too sharp for you, try this recipe with orange slices instead. If you have trouble removing the pith, dip grapefruit into boiling water for a few seconds.