In a deep pan add 3 tablespoons of olive oil and cook the garlic and onion till the onion is translucent.
Making Caldo Verde in an Open Pot:
Add the potatoes and stir fry till the potatoes are a little soft. Add the water and let it come to a boil.
Lower the flame and cook covered for about 30 minutes till the potatoes cook till mushy.
Making Caldo Verdo in the Pressure cooker:
In the pressure cooker pan add 3 tablespoons of olive oil and cook the garlic and onion till the onion is translucent.
Add the potatoes and stir fry till the potatoes are a little soft. Add the water to cover the potatoes and close the pressure cooker lid. Cook for 2 whistles. Once the ptressure drop naturally open the lid.
Mash the potatoes with a potato masher or use the hand mixer to make a smooth broth. You can also cool it and use the blender or for the processor. (for an easy hack see notes).
There are people who use sausages in this soup so fry the thinly sliced sausage and add to the soup. Add salt and pepper too. Simmer for 5 minutes.
Before serving stir in the spinach cut in thin ribbons and bring to a boil. (I do not as we prefer our palak uncooked).
Serve with bread and top it with olives if you like them.
Notes
A simple hack to this soup I follow is that I pressure cook my potatoes and then mash them then add the water to the pan. Add about a litre of water you can always add more water if your broth is thick.
In case you want to avoid potatoes once the onions are fried add water then add a slurry of cornflour or all-purpose flour to thicken the broth to your taste. 1 tablespoon per cup of soup is the measure.
In case you want to avoid potatoes in my Caldo Verde Soup use cornstarch (or cornflour) to thicken your soup. Please note now your soup is not gluten-free.
You can add dairy milk to the soup just before you serve and bring it to a boil.
Fry thinly sliced sausage and add to the soup.
If you plan to store Caldo Verde do not add the greens in the broth. Cool the batch fully before freeing it in air-tight containers.