This dessert is pretty simple to put together, but spectacular to serve. Start this a day ahead to freeze the granita and set the jelly.
2ruby grapefruit, segmented, seeds discarded4 eachmandarins and limes, segmented, seeds discardedBlood orange granita1 litrefreshly squeezed blood orange juice (from about 20 oranges)220 gm(1 cup) white sugarMandarin and ruby grapefruit jelly600 mlfreshly squeezed mandarin juice (from about 20 mandarins)300 mlfreshly squeezed ruby grapefruit juice (from about 4 grapefruit)Juiceof 2 lemons220 gm(1 cup) white sugar6titanium-strength gelatine leaves, softened in cold water for 5 minutes
For blood orange granita, stir blood orange juice and sugar in a saucepan over low heat until sugar dissolves, then pour into a wide, shallow tray and cool to room temperature. Freeze, scraping granita every couple of hours with a fork to form crystals, until frozen (5-6 hours).
For mandarin and ruby grapefruit jelly, stir juices and sugar in a saucepan over low heat until sugar dissolves, then remove from heat. Squeeze excess water from gelatine, add to juice mixture and swirl until dissolved. Pour into a 1-litre jelly mould and refrigerate until set (5-6 hours). Jelly will keep refrigerated for up to a week.
Combine grapefruit, mandarin and lime segments in a bowl. Scrape granita with a fork again just before serving. Dip jelly mould in hot water and gently pull edges of jelly away from sides of mould to break the vacuum. Place a serving plate on top, invert mould and plate, and remove mould. Serve with granita and citrus salad.