Mushroom ketchup

[Goodwitch9]

I once had a lovely brunch dish in a local restaurant that has since sadly closed down. It was basically a rosti with grilled mushrooms and a poached egg on top but what made it so nice was that it had a little dollop of mushroom ketchup on the side. I've tried to recreate it, using the Geo Watkins ketchup from the supermarket but it wasn't the same. The restaurant ketchup was thick and glossy, the supermarket one was tasty but much thinner, more like Worcestershire sauce. Does anyone know where I could buy a thicker version? Or does anyone have a tried-and-tested recipe?

I also have the thiner version , I haven't tried it but could you mix it with a little mayo ? Or perhaps sour cream for a slightly sharper taste ?

Here’s a recipe if you fancied a diy version https://www.greatbritishchefs.com/recipes/mushroom-ketchup-recipe

if not, would a jar of porcini or truffle pesto type stuff work?