Have you ever had a watery soup with only one or two ingredients that was absolutely delicious? Did you ever wonder how they managed to get it infused with so much flavor? Did you suspect them of using broth?
You'd be wrong.
It is possible to bring out a vast array of flavors from just a few vegetables and water but you need to know a few tricks first.
The Italians call the technique insaporire – to infuse with flavor.
The first and the hardest part is that you cannot hurry the process. Time is the secret to success here.
The second is that you need to actually drop the vegetables in the "correct" order. The order is actually based on water content something that you will not learn from an Italian nonna's, who know these things instinctively, but since you and the CC aren't of a certain age yet, we resort to science.
The vegetables must be fried in order of least water content to most water content. Onions, leeks, garlic come first, followed by root vegetables like carrot and potato, followed by celery, followed by cooked beans, followed by mushrooms and leafy vegetables come last.
The last part is that you actually need to fry the leafy vegetables not just cook them. They have a ton of water so they need to be both blanched and wrung dry. (The broth can be preserved and added back to the soup when the time of frying is over.)
This really really matters. You cannot hurry the process nor short-circuit it.
What is really happening here?
When you fry vegetables languidly at a medium-low heat, you are basically allowing Maestro Maillard to work his magic.
When you add the water, you are just transferring the rich flavor from the surface of the vegetables to the broth. It allows you to interleave two steps into one and more importantly, do it in an economic manner – something that has always been important in the kitchen.
There are generalizations on this technique. You could use a ton of vegetables. That's what a minestrone really is. Or you could add greens. Or bung in an anchovy. Or a little diced pork. Or some raw shrimp right before serving.
However, the technique of slow frying to build the flavor remains the same.
Let's showcase this with a classic summer recipe.
2 leeks or spring onions (thinly sliced)
1 zucchini (sliced into half-moons)
1/2 cup white beans
2 sprigs rosemary
1 sprig sage
1/2 cup parmigiano-reggiano
Cook the beans with 1 sprig of rosemary and some sea salt. Drain and set aside.
In a medium vessel, heat up some olive oil. When it shimmers, add the leeks and turn the heat to medium-low. Let it cook languidly for at least 10 minutes. Make sure they don't brown. Add the black pepper.
Add the zucchini and let it cook languidly for at least 10 minutes till the zucchini is limp but not falling apart. It may be browned in places which is fine.
Add the beans and cook for an additional 5 minutes.
Add the water and bring to a boil. Serve at once topped with the parmigiano-reggiano and additional black pepper. Crusty bread works its charm here.