Preheat the oven to 400⁰F. Line a shallow baking tray with baking paper. Peel, quarter and core the pears and toss with the oil. Arrange on the baking tray in a single layer. Roast pears for 40-45 minutes, turning the pears every 15 minutes. In the final 15 minutes of roasting, sprinkle over the bacon lardons and in the final 5 minutes, sprinkle over the pecans. Serve roasted pears drizzled with the vanilla vinaigrette (recipe below).
In a small bowl place the vinegar, Dijon mustard, brown sugar and vanilla seeds. Whisk to combine. Drizzle in the olive oil, whisking well until emulsified. Alternatively, make vinaigrette in a screw-top jar and shake well before using.