(Deb Lindsey for The Washington Post)

At the risk of sounding like a “Portlandia” sketch, there’s one way to elevate a salad, a sandwich, even many a main course, and that’s to put a pickle on it. Or in it. Or around it.

Why? It’s largely a matter of that sourness, of course: just the touch you need to cut through rich elements. But a close second would be the almighty crunch. Because vegetarian cooking often needs special attention paid to texture (which can be one-dimensional in the hands of less-experienced practitioners), pickles provide a dose of variety.

The king of pickles is also the smallest: the cornichon. They’re not just for the cheese or (heaven forbid) charcuterie tray anymore, either. Chop up a few of these little French babies, use them to garnish a pureed vegetable soup or toss them into a salad dressing, and you’ll see what I mean.

It’s the latter that Anna Jones does to such good effect in a warm salad of roasted spring vegetables (asparagus and new potatoes). In her beautiful new book, “A Modern Way to Eat,” this former Jamie Oliver protege, who has also worked with the eminent Yotam Ottolenghi, demonstrates that she’s got plenty of smart cooking lessons to teach. Besides those cornichons in her salad dressing, she makes a Spanish-style tortilla with sweet potatoes and tops it with an almond salsa; roasts radishes with honey; and dresses whole-wheat spaghetti with little more than avocados, herbs and lemon zest.

But back to that salad. Another smart thing about it is something that may at first glance seems like no big deal. While the vegetables cook, you put together the thick dressing of watercress, herbs, oil, vinegar, mustard, capers and those cornichons. Here’s the important step: You roughly chop all that and whisk or shake in a jar to combine, rather than whir them together in a food processor or blender. The vibe is loose, and the dressing sharp and multidimensional.

There’s one more touch: You hold out a few raw asparagus stems and cut them into strips with a vegetable peeler. Another layer of taste and texture, another layer of brilliance.