Pork tenderloin with roasted potatoes and mushrooms

I am definitely not the type of cook who writes down specific recipes, so I'll try my best! This is an easy weeknight dinner for us because most of goes in the oven for the same temp and time- with only one frying pan on the stove. Pork tenderloin is on sale at least once every few weeks - so we stock up and keep them in the freezer.

Pork
1 pork tenderloin (they often sell these in two packs so we will cook two and have leftovers for lunches)
1 to 2 tsp salt (we use kosher salt)
1/2 tsp black pepper
1 to 2 tsp chopped rosemary
1/2 tsp thyme leaves
2-3 tbsp olive oil

Mix the salt, pepper, rosemary, and thyme with the olive oil so it makes a sort of paste. Put the pork tenderloin in a 9x13 glass dish and spread the mixture on the pork. You can tweak the topping to your taste (more or less salt/rosemary/pepper) - you could add red pepper flakes if you want it a little spicy.

Put it in a 400 degree oven for around 20 minutes.  If it's a super big one it might take more like 25. You can use a meat thermometer, it should be at about 150, I think. I also just do the poke test - if it is firm to the touch, it is probably done! Let it rest for 5ish minutes, then slice and serve.

Potatoes
Chop any type of potato into 1 inch cubes or so. I like red potatoes because I don't have to peel them! Spread them out on a sheet tray and drizzle over enough olive oil to coat them. It also sometimes helps to put a little oil on the tray itself before you put on the potatoes so they don't stick. Sprinkle on salt, pepper, and maybe some rosemary if you have extra. Put in at the same time as the pork - they should finish up just about when the pork is done resting. Flip them over once during the cooking. They should be nice and crispy.

Mushrooms
Cut one container of white mushrooms into quarters. Put in frying pan with 1 tbsp of butter, 1 tsp of salt, and a little pepper. Saute on medium heat until the mushrooms are soft. Probably about 10 minutes.

Bonus Sauce: My family makes a "pork sauce" that is purely to use up things in the door of the fridge. Mix together 3 parts jam with 1 part mustard in a small saucepan. Doesn't matter what kind of any of these! Add in a splash of water or juice (really...anything!) and some salt and pepper and simmer until it is thick. I know it sounds crazy - but it's delicious!