To make the pesto, place the basil, garlic, walnuts and Parmesan cheese in the food processor; season with salt and pepper, and blend. While the food processor is on, pour the olive oil slowly into the mixture. Spread the pesto equally on the slices of bread and place the bread in a toaster for two minutes. Then place the mozzarella cheese, tomatoes and roasted red peppers on top of bread slices and allow the cheese to melt and the veggies to soften. Once the cheese melts, close the sandwich, cut and serve immediately.