Combine half and half, salt and rose petals in medium saucepan. Bring to steaming over medium heat, stirring frequently, for 10 minutes. Meanwhile, whisk sugar with egg yolks until pale, creamy, and well-combined.
Strain rose petals from half & half and return to saucepan. Whisk 1/2 cup of hot half & half into egg yolks. Repeat process several times to temper egg mixture.
Pour tempered egg mixture into saucepan along with heavy cream. Cook custard over medium heat, stirring constantly until thick enough to coat back of spoon (about 3 minutes). Turn off heat and strain through a sieve into large bowl. Add vodka, olive oil, and whisk to combine.
Cover and chill minimum 2 hours, or overnight.
Freeze according to manufacturer’s instructions for ice-cream maker model.
Process custard based on your ice cream machine's instructions. If adding almond brittle to ice cream, add coarsely chopped brittle during last few minutes of churning.