Blistered, warm, juicy tomatoes add another dimension to this grilled garlic bread bruschetta.
Combine all of the ingredients together and refrigerate until ready to use.
Add the basil, parsley, garlic, walnuts, and salt to the bowl of a food processor. Pulse several times to chop everything together coarsely, then, with the machine running, pour in the ½ cup of olive oil in a slow steady, stream.
To store and use the pesto later, scrape the pesto from the food processor into a small jar or container. Smooth the top surface, and cover it with a thin layer of olive oil or a piece of plastic wrap to prevent discoloration. Refrigerate for a week, or freeze for several months. Warm to room temperature before using.
Heat grill to medium high heat, about 350 degrees. Thread the grape or cherry tomatoes onto a bamboo skewer and grill, turning frequently, until they are blistered and warmed through. Spread the garlic butter on each of the bread slices and grill until toasted and lightly charred. Spread each piece of grilled bread with 1 teaspoon of the basil pesto. Add 1 slice of mozarella to the bread and top with the warmed tomato. Garnish with additionla pesto, if desired.