Preheat oven to 375 degrees. Spread walnuts in a single layer on a small rimmed baking sheet, and toast until fragrant and browned, 7 to 9 minutes. Remove from heat; let cool, and roughly chop. Set aside.
Heat oil in a small saucepan over medium heat. Add shallot, and saute until softened, about 2 minutes. Add pears, vinegar, honey, and cloves. Bring to a boil, reduce heat, and cook until pears are tender, 4 to 5 minutes. Discard cloves, and stir in raisins and reserved walnuts. Remove from heat. Serve warm or at room temperature.