Place covered satsumas (peeled and separated) in the freezer for approximately 1/2 to 1 hour - until frozen.
In a dry 3-quart heavy saucepan cook 1/4 cup sugar, undisturbed, over moderate heat until it begins to melt and cook, stirring with a fork, until melted completely and deep golden brown. Remove pan from heat and dip pan briefly into a bowl of ice water to stop cooking. Caramel solution will harden. Cool pan about 5 minutes and return to heat. Add milk and cook over moderate heat, whisking, until caramel solution is melted. Whisk in cocoa until combined well and keep mixture warm.
In a metal bowl set over a saucepan of barely simmering water (or a double boiler), melt chocolate, stirring, and remove from heat.
In a bowl with an electric mixer, beat egg yolks with remaining 3/4 cup sugar, lemon juice and satsuma juice until thick and pale. Whisk in caramel mixture and chocolate in streams, whisking until combined. Pour custard into another 3-quart heavy saucepan and cook over moderately low heat, stirring constantly, until a candy thermometer registers 140&
Take the frozen satsumas and dice into small chunks. Fold in the satsuma chunks into the cooled custard.
Freeze in an ice-cream maker according to manufacturer's instructions.
Gelato will keep in the freezer for no longer than a few days.
Makes about 3 cups.
Garnish gelato with fresh satsuma slices and mint leaf (if you want to be fancy about it).
So now that you know what they are, if you're lucky enough to get your hands on some of these Louisiana gems, check out our recipe section for some awesome Satsuma recipes!