What could be used as a savoury custard to serve with a savoury jam roly-poly? I'm not mad, you know.

I have this plan to serve a meal backwards - coffee and brandy, then dessert, then a main, then starters, then champagne. Except that of course each stage will be tailored to work in the actual order, which mostly means making a savoury dessert and a sweet starter.

Honestly, i'm really not mad. I've been tested.

For the savoury dessert, i plan to make that celebrated stodgy English treat, jam roly-poly. To make it savoury, i will use something like red pesto instead of jam. Or it might be a savoury version of some other suet pudding - spotted dick or figgie hobbin with olives instead of currants, perhaps.

Pudding needs custard. What can i use as a savoury custard?

One option is simply to make a savoury custard. Cream, eggs, no sugar, and perhaps black pepper instead of vanilla. Would that work from a purely physico-chemical point of view? Would it be disgusting? Apparently it works on top of moussaka, but that's a baked custard.

How about a Béchamel sauce, or some derivative of it? Perhaps with some cheese, to make it a custardy yellow and give it more interest?

A Hollandaise sauce might be the closest thing to a savoury custard, what with having eggs in. I've never made one, though, and it looks too difficult for me.

Any thoughts?
I think a savory cheese spread would be a good complement. Maybe something like Boursin cheese, perhaps blended with sour cream.