Prepare the pork tenderloin by removing the silverskin and any visible fat. Butterfly the tenderloin, but cutting it in half lengthwise, cutting almost, but not quite, all the way through. Spread it open and flatten slightly. Season with a bit of salt and freshly ground pepper.
Prepare the Souvlaki marinade by stirring together all the marinade ingredients in a small bowl. Rub on the prepared pork tenderloin, then place in a plastic storage bag or wrap well with plastic wrap and refrigerate to marinate at least 30 minutes or up to 8 hours (the longer the better).
* Both the Tzatziki and Marinated Cherry Tomatoes can also be made ahead and refrigerated, if you prefer. (see below for instructions).
When ready to cook, preheat oven to 375F (not fan assisted).
Remove the marinated pork tenderloin and place it on a baking sheet (you can line with foil, if you like). *I like to tuck the smashed garlic cloves underneath the pork, so they don't burn on the top and introduce a bitter flavour. You can also just remove and discard, if you like. Place in preheated oven and allow to cook until it reaches 145F internal temperature, about 20 minutes. Brown the top of the pork by popping it under the broiler for a few minutes.
While pork is cooking, prepare the marinated cherry tomatoes by combining all the ingredients in a medium bowl and tossing well to combine. Set aside at room temperature to marinate until needed. Prepare the tzatziki by combining all the ingredients in a small bowl and stirring well to combine. Allow to sit at room temperature until needed.
When pork is done, allow to rest a few minutes, then remove to a cutting board and cut into slices. Serve with the marinated tomatoes and some tzatziki. Some warmed pita bread triangles drizzled with a bit of garlic butter would also be a nice addition to the platter, if you like.
Nutritional information does not include optional cherry tomato salad.While I've detailed the non-BBQ method here, you can certainly take these same ingredients and instructions and cook the pork on the BBQ instead. Either do it butterflied, as I have done here, or you can cube the pork tenderloin and thread onto skewers for the grill, if you prefer.Be sure to read the “Ingredient and Cook's Notes" (above the recipe card!), where I share more detailed tips, variations and substitution suggestions for this recipe!