The best sauce to make with veloute is Suprême sauce.
It's veloute enhanced with butter, cream, and lemon juice.
It's an absolute stunner for charred asparagus, broccoli, Brussel spouts, or fingerling potatoes.
Protein of roasted whole/half/quarter chicken goes well with it all.
I like to spike it as well with some nice Brazilian pink peppercorn, which give it a brighter, fruiter pepper taste.
Or hit it with some nice seasoning soy sauce like Maggi.