Pat the scallops and beef tenderloin really dry and sprinkle the beef generously with salt.
Melt a few tablespoons of ghee in a skillet (cast iron preferred) that's been set over thermonuclear heat. When the pan is scorching hot, add the sea scallops and sear them for about 30-45 seconds per side, until a nice golden crust forms.
Remove the scallops to a plate, add more fat to the pan and add the beef tenderloin. Sear the piece of meat on all sides until it gets beautifully brown and crusted all around.
Let the meat cool for a few minutes then place the scallops and tenderloin in two separate re-sealable bags.
Combine all the ingredients of the marinade in a glass measuring cup or small mixing bowl, preferably one that's equipped with a pouring spout.
Pour the marinade over the scallops and beef, seal the bags (remove as much air as possible) and refrigerate for at least 4 hours or better yet, overnight.
While the meat is marinating, make the infused oil. Put all the ingredients listed under "infused oil" in a small saucepan set over low heat and bring this to a slow simmer, which should take about 4 to 5 minutes, then remove from heat. Let the oil cool down to room temperature, at least 3 hours, then strain it through a fine mesh sieve. Set aside until ready to use (you might want to store it in some kind of a jar if you’re not going to use it until the next day).
On a wooden board, chop the raw pistachios very finely and mix in the zest of half an orange. Remove the beef from the marinade, let it drip for a few seconds and then roll it in the chopped pistachios until it's completely coated.
Slice the meat thinly against the grain and arrange it on a serving platter, leaving a great big space in the middle for the scallops.
Remove the scallops from the marinade and slice them lengthwise into 4 thin slices. Arrange them on the platter with the beef.
Sprinkle with some of the chopped pistachios that got left behind during the crusting process, drizzle generously with the infused oil and serve.