Despite the simplicity of this tart — the only ingredients are three vegetables and a few seasonings — it delivers big flavor in a beautiful package.

The secret is in the layering. Yukon Gold potatoes, onion and butternut squash are sliced paper-thin, then arranged layer upon layer in a pan. As you stack, chopped fresh herbs are sprinkled between those layers, then the whole thing is roasted until the vegetables are buttery tender.

The result is a delicious tart that is vegan, yet filling. A mandoline is the best choice for getting the vegetables paper-thin. If you don’t have one, use a food processor fitted with the thinnest slicing attachment. And if you prefer, sweet potatoes can be substituted for the Yukon Gold.