For better soups, start in the oven

But lesson one is the foundation for a lot of the soups I make at home: Start in the oven.

I don’t mean every soup. Some soups depend on freshness, delicacy or a particularly clean broth, and I’ll get to those. But when I want depth, sweetness, browning and the kind of flavor that tastes like something has been cooking much longer than it actually has, I start by roasting.

Here’s the method.

Mine started with garlic, red onion, sun-dried tomatoes, cherry tomatoes, fennel, olive oil, spices and an anchovy or two, all piled into a Dutch oven and roasted together.

The oven transformed every ingredient differently. The onion and fennel softened, browned and grew sweeter. The anchovy sizzled itself into the oil coating those browned alliums. The cherry tomatoes burst, their skins turning silky and their juices almost pasty around the edges. The sun-dried tomatoes somehow became even more concentrated. The spices perfumed absolutely everything.

By the time the pot came out of the oven, most of the flavor was already there.

That, to me, is the whole appeal of the method. You can build a similar kind of depth on the stovetop, of course, but the oven does a lot of the work for you. Dry heat browns, evaporates and concentrates while you go do something else.

And when you roast, push things a little farther than may initially feel instinctive.

Your vegetables should not be pretty anymore. I want onions slumped and browned at the edges. Tomatoes wrinkled and burst. Mushrooms dark. Carrots blistered. Bits sticking to the bottom of the pot. If everything still looks ready for a glossy farmers market photo shoot, give it another few minutes. This works beautifully with fresh vegetables, but frozen vegetables are welcome, too. So are drained canned beans. 

Douse whatever you have in oil, season it well and let it get ugly.

This is also when I deploy what I lovingly think of as my potions and powders: anchovy, tomato paste, miso, soy sauce, fish sauce, bouillon paste or cubes, mushroom and brown gravy powder.

Not all at once, obviously, though I respect the chaos.

The point is to let those deeply savory ingredients spend some time in the heat rather than simply dissolving them into broth at the end. Tomato paste darkens. Anchovy melts into the oil. Spices bloom. Everything has a chance to mingle before the soup gets diluted.

Once everything is properly roasted, I add just enough broth to loosen the browned, sticky bits from the bottom of the pot. Not a carton. Not even close. At this point, the broth isn’t there to create the flavor. It’s there to capture what the oven already made.

Scrape thoroughly. Those dark little bits on the bottom are part of the soup now.

For a lot of vegetable, bean and chowder-style soups, I blend about half of what’s in the pot.That gives you body without turning the whole thing into purée. The blended vegetables thicken the broth, while the rest keep enough texture to remind you what you’re eating.

You can do this in a blender or with an immersion blender (though I tend to like the control of scooping part of the mixture into a blender and leaving the rest alone.)

Here is the part that feels a little counterintuitive: after going to the trouble of deglazing the pot, I often cook everything back down again. I let the blended and unblended mixture simmer until it gets thick, concentrated and almost sticky. Then I add my final stock, cream or coconut cream until the soup reaches the consistency I actually want.

This is one of my strongest soup opinions: don’t drown the thing you just concentrated.

You can always add more broth. You cannot easily take it back out (though, if you do, it’s not the end of the world: just let the soup reduce longer.) 

Once the texture is right, I finish with whatever gives the soup its final bit of life: herbs, citrus zest, salt, black pepper, maybe cream. Those ingredients don’t need half an hour in the oven. They need to stay bright.

Once I noticed this pattern, I realized it’s how I make most of my favorite soups: tomato soup, corn chowders, vegetable soups, bean soups and even chicken soup.

For chicken soup, I roast thighs on a bed of onion, garlic, carrot and celery with big lemon slices, garlic powder, onion powder and plenty of black pepper. Once the chicken is cooked, I pull it out to shred later, while the vegetables underneath — softened in chicken fat, lemon and all those browned juices — become the base of the soup.

I am certainly not claiming to have invented roasted chicken soup. Italian penicillin nonnas have been several centuries ahead of me on that front. But the example stands.

Roast first. Deglaze. Blend some. Reduce. Reconstitute. Finish.

There are plenty of soups I would never subject to this treatment.

If I want something fresh, delicate or particularly clean-tasting, I stay on the stovetop. A clear miso broth with beautiful soft cubes of tofu doesn’t need caramelization. Neither does a simple cream of potato or parsnip soup (more on those next week!), or a bright, stewy pozole verde.

My spring pea soup — peas, stock, cream, dill, black pepper and lemon zest — absolutely does not belong in the oven. She is delicate. Leave her alone.

But if the goal is depth, browning and concentration, this is the pattern I come back to over and over.

Take the vegetables you have. Fresh or frozen. Add some canned beans if you’ve got them. Douse the whole situation in oil and spices and roast until things get a little ugly. Deglaze. Blend some of it. Reduce it. Add broth carefully. Finish it with whatever makes sense.

It is not a precise science. It is not particularly pretty.

It is, however, delicious.

This is a current variation on roasted tomato soup I’ve been making a lot recently: warmly spiced with garam masala, fennel and coriander, rounded out with miso and coconut cream. Garam masala is an Indian spice blend whose exact makeup varies, but it commonly includes warming spices like cumin, cardamom, cinnamon, cloves and black pepper.

This story originally appeared in The Bite, my weekly food newsletter for Salon. If you enjoyed it and would like more essays, recipes, technique explainers and interviews sent straight to your inbox, subscribe here.