How much more milk and/or oats should be used to compensate for absorption if i opt to steep the oats with only the milk, then make the custard ba...

Just to let you know...I channeled David, all the way! Heated up the sugar with the milk, half the cream, and vanilla pod (which I couldn't resist seeding and adding most of the seeds to the mixture). Took the liberty of adding a dash of cinnamon, too. Let the oats steep off heat for 30 minutes - (it scared me to have milk over a medium heat for 20 minutes). Strained and squeezed the oats back into the milk mixture and, man, what a wonderfully interesting flavor! I even had a 1/4 cup or so of extra oaty, milky goodness. Made the custard as David would; now it is all chilling in fridge. Could be YUMMY!

Well, the recipe uses 4 1/4 cups of milk and cream to get to 3 3/4, so that means half a cup of oats should absorb around half a cup of liquid. If you want to add more oats to intensify the oat flavour, I would try adding an equal volume of extra milk to compensate for the absorption. As for how much extra oats you'd need to get the same flavour, you'd need to experiment. I'd probably try 2/3 cup of oats instead of 1/2 cup and add an extra 2-3 tbsp of milk.

Alternately, you could try steeping the oats in the milk and half of the cream, and then add the other half of the cream at the end. That will preserve some of the fresh taste of the cream but will have a smaller impact on the concentration of the oat infusion.