Juice your apples and watercress. Blend with the avocado and the juice from your lemon.
If you like, feed the flesh from your avocado (and your lemon if you peel it first) through your juicer, though it won’t be as creamy.
* Keep your avocado in a paper bag for a day or two and it should ripen just nicely. Stick a banana in the bag too and it’ll ripen even faster.