Add the red onion and coriander to the Thermomix bowl and chop for 3 sec/speed 7. Scrape down the bowl.
Add the tomato and chop 3 sec/speed 6. Scrape down the bowl.
Add the avocado and lime juice and mix for 2 sec/reverse/speed 5. Check for consistency and mix again for 1-2 sec/reverse/speed 5 if you want it less chunky.
After mixing, stir in salt and extra lime juice to taste gently with a spoon. If desired, add some sliced jalapeno peppers.
Notes
Storage: To store the Guacamole, place it in an airtight container, squeeze a little lime juice on the surface, and press cling film on it as best you can (see the photo in the recipe post). It will last two days in the fridge.