How would I cook this @betarhoalphadelta ?
Definitely options. The "traditional" Santa Maria is seasoned with salt/pepper/garlic (SPG), cooked over live fire oak wood, on a grate that can be raised and lowered to adjust the amount of heat you're exposing it to, so that you get a nice sear on the outside and the inside to your appropriate doneness.
I recommend the traditional Santa Maria seasoning. SPG is just always good. You can hit it with some olive oil first for the seasoning to adhere to the meat, although I usually hit it with Worcestershire sauce. If you want to get spicy, rub it with some Sriracha and then hit it with SPG. You can season pretty liberally because the steak will be sliced (more on that below) and each slice will only have a little bit of seasoned surface area. Give it 10 minutes for the seasoning to set on the surface (in the fridge / leave out is your choice), and you're ready to cook.
But overall it's just a big steak. For something like this I'd go either sear/finish or reverse sear, because you don't want to char the crap out of it and have a raw center. But you know meat well enough not to do that, so I don't have to tell you that. I prefer sear-first but I know a lot of people disagree on that. You want to cook to medium rare or at MOST medium. IIRC you are less of a medium rare fan, but it's a leaner cut and if you go past medium it's going to be a little dry. It's really not a hard cut to cook. Despite the shape they're usually pretty uniformly thick across the whole thing so they cook surprisingly evenly. Let it rest (as you would any thick piece of meat), and then slice it.
The bigger thing is how to slice it. See below. The blue line is where there will be a bit of a seam of fat. The grain of the meat runs in different directions on either side of the grain. And since you want to slice across the grain, that can be a slight problem. How you get around that is cutting it into two pieces before you slice it.
The blue line is that fat seam. Slice it there first. Then cut each individual piece across the orange lines. Generally (as Michael Symon suggests) you want to cut it to the width of a #2 pencil. It's naturally a tougher piece of meat, but cut that way it will have a nice chew without being "chewy" or tough.
Personally I don't think it needs a sauce. Nor even adornment, although a good chimichurri is quite nice on it. Leftovers are great for sandwiches--although nobody ever sees
leftover tri tip in this house

