Step 1Place a rack in the lower area of the oven; heat the oven to 400 degrees.
Step 2Place the potatoes in an 8-inch square baking pan and toss them with the oil. Season with salt and pepper to taste. Bake the potatoes, shaking the pan every 10 minutes to turn them, until they're just tender, about 30 minutes depending on their size. Check tenderness with the point of a paring knife. Add the mushrooms and season with salt and pepper. Drizzle the potatoes and mushrooms with 1 tablespoon of pesto.
Step 3Bake until the mushrooms are hot but still firm, shaking the pan once to mix the ingredients, about 5 to 7 minutes more. Remove the pan from the oven and toss the potatoes and mushrooms with the remaining pesto. Season to taste. Serve hot, attractively arranged on plates with the chops.