Wash the lime hot and dab dry. Cut one half into thin slices and squeeze the juice from the second half. Whisk egg yolks, icing sugar, except for 1 tablespoon for dusting, and 1/2 teaspoon cinnamon in a hot water bath until foamy.
Add the port wine and lime juice, continue beating until the sauce becomes creamy and thick and remove from the water bath. Carefully wash the figs, dab dry and cut into quarters. Peel the skin of the Cape gooseberries and press them under the fruit berry.
Divide 2/3 of the port wine sauce between 4 plates. Place figs and Cape gooseberries on the plates. Drizzle the fruit with the rest of the sauce. Garnish plates with the lime slices and mint leaves and serve dusted with the remaining icing sugar and cinnamon.