method
1. Peel, stone and dice the avocado.
2. Blanch the tomato for 30 seconds in boiling water then peel.
3. Put the avocado, tomato and onion into a blender.
4. Add the lemon juice and zest, the oil and salt and pepper to taste and puree until creamy.
5. Add the sauce to grilled/broiled vegetables or pour over cold, boiled rice.
