Preheat your oven to 400°F / 200°C.
Slice the polenta log into ¼-inch-thick rounds, then cut each round into ¼-inch-thick strips.
Arrange the polenta strips in a single layer on a nonstick baking sheet. Lightly brush them with olive oil and sprinkle generously with salt and pepper.
Bake for about 15 minutes, turning once halfway through, until the strips are golden and slightly crisp.
Set aside to cool.
While the polenta bakes, prepare the salad.
In a large salad bowl, combine the mixed greens, chopped red onion, and minced celery.
Peel, core, and dice or thinly slice the pears.
Place them in a separate small bowl and toss with 1 tablespoon (15 ml / 0.5 fl oz) of the lemon juice to prevent browning.
Add about three-quarters of the pears to the large salad bowl.
To make the dressing, place the remaining one-quarter of the diced pears into a food processor or blender.
Add the remaining 2 tablespoons (30 ml / 1 fl oz) of lemon juice, the brown sugar, and a pinch of salt and pepper.
With the machine running, slowly drizzle in the ¼ cup of olive oil until the dressing is smooth and emulsified.
Pour the pear vinaigrette over the salad and toss gently to combine.
Top with the toasted pecans and the cooled, crispy polenta strips.
Serve immediately.
