Preheat the oven to 375 degrees F (190 degrees C).
Heat the olive oil in a large skillet over medium-high heat. Coat the pork tenderloin with flour, and brown in the hot skillet on all sides. Transfer to a casserole dish. In a medium bowl, mix together the salad dressing, honey and onion soup mix. Slather
the tenderloin with this mixture.
Cover the dish, and bake for 1 1/2 hours in the preheated oven. Pork should be fork tender.