I like to sear the fatty side of the tri-tip for a few minutes in my cast iron pan on the stove, then put it in the oven in my turkey pan with the rack. I cook it for roughly 45 minutes and slice it thin quickly after taking it out.
I never get leftovers as my kids turn into extreme carnivores and eat the whole thing minus the few thin pieces I get
It is one of their favorite things I cook.