Preheat oven to 400 degrees.
Place carrots on a large, rimmed baking sheet and toss with 1 tablespoon of olive oil. Cover with aluminum foil and roast for 15 minutes.
In a small bowl combine mustard-thyme rub ingredients. Whisk until smooth.
After trimming pork tenderloins, rub pork with half of the mustard-thyme mixture.
In a large skillet over medium-high heat drizzle 1 tbsp olive oil and place pork, one tenderloin at a time, into skillet. Sear tenderloin on all sides. This should take about 8-10 minutes per tenderloin.
Once carrots are done cooking, remove from oven and divide between two baking sheets. Add half of the onions and apples to each sheet. Drizzle each tray of vegetables with 1 tablespoon of olive oil and ¼ teaspoon salt and pepper.
Nestle pork into the vegetables and rub remaining mustard-thyme mixture onto pork. Return trays to oven, uncovered, for another 20-22 minutes.
Pork is done cooking when the internal temperature reaches 130-140 degrees Fahrenheit.
Let pork sit at room temperature for 10 minutes. Serve and enjoy!