My guess was they grilled it first to sear it on the outside and then put it in the water at a lower temperature to cook it all the way kinda sous vide style
The water would make it soggy. Personally, I sear my roast beef on all side and then deglaze the burnt meat residue to turn into the sauce, but if you want crispy edges you'd want to keep the water away from it.
The water would make it soggy. Personally, I sear my roast beef on all side and then deglaze the burnt meat residue to turn into the sauce, but if you want crispy edges you'd want to keep the water away from it.