To make the vegetable stock, start by roughly chopping 2 onions, 3-4 carrots, and 3-4 celery stalks. Add these to a gallon-sized pot along with a dollop of oil. Let the veggies sweat until they are just starting to soften (approx. 10 minutes).
Fill the pot to the brim with cold water and add 1/2 parsley bunch, 10-15 whole black peppercorns, and 2 bay leaves.
Bring to a boil and then reduce heat to a simmer. Let simmer for about an hour (or longer if you want).
Strain the stock. You can keep the veggies around to munch on if you want. You'll need 5 cups of this stock for the Avocado Soup. Store leftover stock in the fridge where it will keep for at least a few days, or in the freezer where it will keep for months.
To make the Avocado Soup, start by cooking 1/2 onion, 1/4 jalapeno and 1 garlic clove in a dollop of oil over medium heat. When the onion is softened and just starting to brown (5-8 minutes), add the mixture to a blender or food processor along with 5 cups of stock, 15-20 sprigs of cilantro, the juice of 1 lime, 1/2 teaspoon salt, and some freshly cracked black pepper. Combine well.
Add the flesh of 2 avocados and pulse blend (I usually leave the avocados chunky). Taste for seasoning. I added another 1/4 teaspoon salt (so that is 3/4 teaspoon total) and another squeeze of lime.
This is typically served lukewarm or chilled. If you are using freshly made stock you can serve it right out of the blender, otherwise you can warm it up lightly in a saucepan over mediumish heat.
Additional garnishes include Crema, black pepper, and definitely a final burst of acidity (lime juice or hot sauce).
Store leftovers in an airtight container in the fridge.