In a small bowl, whisk together cornstarch and 1/2 cup of the milk until smooth.
In a medium-sized saucepan, whisk together remaining 1 1/4 cups milk, sugar, honey, and salt.
Whisk in the milk and cornstarch mixture.
Heat on medium high heat until it begins to bubble but isn't quite boiling.
Whisk egg yolks in large bowl.
Whisking rapidly and pouring very slowly, add about 1/2 of the hot milk mixture to the egg yolks. If you add too much hot liquid at once to the egg yolks, you risk cooking them.
Pour the egg yolks plus milk mixture back into the pot and place on medium heat until it reaches 170 F (this should take about 5 minutes), stirring the whole time. It is very important that the liquid not boil as that will cause it to curdle.
Remove from heat and mix in heavy whipping cream and vanilla.
Cover bowl with plastic wrap, pressing the wrap right up against the custard, and refrigerate for at least four hours.
Churn in an ice cream maker according to the manufacturer's instructions.
If you don't plan to add any mix-ins, you can eat it right away. However, if you plan to turn it into a concrete (which you should definitely do), freeze the custard for a couple of hours to harden it. Blending in the mix-ins will make the frozen custard softer, so starting with a harder custard will get you to the right consistency in the end.
Just before serving, use an immersion blender or counter-top blender to add your mix-ins.
If it's a little too soft after blending, return to the freezer for just five minutes and then eat! If you want an authentic experience, make your friends and family stand in a long line before serving.