Combine the strawberries, onion, pepper, cucumber, garlic and basil leaves in a high speed blender or the bowl of a food processor and blend the mixture until smooth. Add in the balsamic vinegar and olive oil. Season with salt and pepper and blend again. If the mixture is too thick, you can add a little bit of water to thin it out. Chill the soup until you’re ready to serve it. Garnish the soup with toasted slivered almonds and a splash of extra-virgin olive oil.