You will be able to cook your pork tenderloin and the potatoes together in one oven. Start with the Oven Roasted Potatoes and put them in the oven. Then start preparing the pork. I like to use my cast iron skillet so I can put the skillet from stovetop into oven for a one-pan, one oven meal. Sear the pork as soon as you have it ready, and then begin with the next step. You should have 15 minutes or so to finish the pork in the oven so your meal is ready at the same time. Make sure the potatoes are done, then turn the oven off while the pork rests for 10 minutes.
Dice in 1/4-1/2" squares, 1/2 cup of the leftover pork. Save for Meal 4 to use in the Quesadillas.