Preheat your oven to 350°F / 175°C.
Spread the walnut pieces on a baking sheet and toast for 7 to 10 minutes, shaking the pan occasionally, until they are fragrant and lightly browned. 2.
Transfer the warm, toasted walnuts to the bowl of a food processor.
Add the cannellini beans, lemon juice, minced garlic, olive oil, and ¼ cup of water. Purée the mixture until it's smooth and creamy.
Season with salt and pepper to your liking. 3. To assemble the sandwiches, spread a generous 3 tablespoons (45 ml / 1.5 fl oz) of the Walnut Pâté on each of 8 bread slices.
Layer each with a roasted red pepper half, a few pear slices, and ¼ cup of baby arugula.
Spread the remaining 8 bread slices with 1 tablespoon (15 ml / 0.5 fl oz) of pâté and place them on top to complete the sandwiches.