Preheat the oven to 350 degrees F.
Toss the pears with olive oil and roast for 30 minutes. Turn the pears over halfway through cooking.
Roast the hazelnuts with the pears for 5 to 6 minutes. Coarsely chop the hazelnuts and set aside.
Place the Taleggio in a heatproof dish or pan and toss into the oven for 3 to 4 minutes.
Heat a grill pan to medium-high heat. (If you don't have a grill pan and are using a regular grill, put foil on the grill grates.) Toss the romaine quarters in olive oil and salt; grill until slightly charred and wilted, 1 to 2 minutes per side.
Place one romaine wedge on each plate. Thinly slice each pear half and fan over the romaine wedges. Spoon some melted Taleggio on top and sprinkle with hazelnuts.
Whisk together the champagne vinegar and 1/4 cup olive oil, and season with salt. Drizzle each salad with a little vinaigrette. Serve immediately.