Preheat oven to 325 degrees F. In a large heat proof bowl whisk yolks, sugar and vanilla extract together.
In a medium saucepan heat half & half, honey and lemon zest on low heat until honey melts, whisk well.
Whisk a few tablespoons of half & half mixture into eggs to temper them, slowly pour the rest in, whisking the entire time.
Put 5 small 1/2 cup-sized ramekins into a large baking pan making sure there is space between each one. Divide custard batter evenly between them. Put the pan in the oven and then carefully pour hot water (not boiling) in the pan until it reaches halfway up the sides of the ramekins.
Bake 40-45 minutes or until custard is set in the middle. Remove from pan, cool on wire racks and chill completely before serving.