Finely grate 2 tablespoons
zest from oranges, then halve oranges and squeeze enough
juice to measure 1/2 cup. Discard oranges.Bring milk,
1/4 cup sugar, a pinch of salt, and 1 tablespoon zest
to a boil in a 2-quart heavy saucepan, then remove from
heat and let steep 30 minutes.
If using Seville oranges,
grate the zest of two of them. Squeeze the juice of
all 3 and pour into a bowl with the zest. If going for
the sweet-orange and lime option, grate the zest of
the orange and one of the limes, juice them.
Strain orange juice,
combine with 90gm sugar and ¼ cup water in a
saucepan, bring to the boil and cook for 5-7 minutes
until a deep golden colour. Cool.Combine cream, milk,
orange rind and Grand Marnier in a heavy-based saucepan
and bring almost to the boil. Combine egg yolks and
remaining sugar in a bowl and whisk until thick and
pale, then gradually whisk in hot milk mixture.
Place a large, heavy-bottomed saucepan
over medium heat. Combine the cream, vanilla, and basil
to the pot. Gently warm the cream over the heat, but
do not let it come to a boil. Remove the saucepan from
the heat when the mixture is just coming to a simmer: