1. The night before, heat oven to 425 degrees . Toss potatoes with 1 tbsp of the oil, 1/8 tsp of the salt and 1/8 tsp of the pepper. Spread onto a rimmed baking sheet. In a small bowl, blend chipotle, 1 tsp of the adobo, the mayonnaise, 2 tsp of the mustard, 1 tsp of the oregano, 1/8 tsp of the salt and remaining 1/8 tsp pepper. Brush onto pork tenderloin on a rimmed baking sheet.
2. Roast potatoes at 425 degrees for 35 minutes, stirring occasionally. Roast pork at 425 degrees for 30 minutes, or until it registers 140 degrees on an instant-read thermometer. Remove from oven and cover pork with foil. Cool both pork and potatoes and refrigerate overnight.
3. Meanwhile, whisk together vinegar, remaining 1 tbsp oil, 1/4 tsp salt, 1 tsp adobo, 1 tsp oregano and the honey. Wrap and store overnight.
4. At dinnertime, in a large bowl, toss together roasted potatoes, salad greens, diced pear and dressing. Divide among 4 bowls. Thinly slice pork and fan on top.