Blitz together the basil, oil, lemon juice and half of the cheddar until a pesto forms. Season with salt and pepper.
Thinly slice a whole avocado through the length (gently lift around the pip). Pack on a serving plate. Repeat with the remaining avocado. Season with salt and pepper.
Top with pesto, remaining cheddar shavings and extra basil. Serve with crackers.
