Secret of veggie tart is the layering
Despite the simplicity of this tart — the only ingredients are three vegetables and seasonings — it delivers big flavour in a pretty package.
The secret is in the layering. Yukon Gold potatoes, onion and butternut squash are sliced paper thin, then arranged in layers 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. If you prefer, sweet potatoes can be substituted for Yukon Gold.
Heat the oven to 375 F. Coat a deep seven- or eight-inch round springform pan with cooking spray.
In a small bowl, mix together the thyme, oregano, rosemary, garlic powder, salt and pepper. Set side.
Use a mandoline or food processor to slice the potatoes, onion and squash as thin as possible. Keep the vegetables in separate piles.
Arrange a single layer of potato slices, slightly overlapping, over the bottom of the prepared pan. Spritz with cooking spray, then sprinkle a pinch of the seasoning blend over them. No need to season heavily.
Top the potatoes with a few onion slices. The onion will break into thin rounds. This is fine. You don’t need a full layer, just a scattering of slices. Top the onions with a single layer of butternut squash slices, slightly overlapping.
Use your hand to gently, but firmly compress the layers. Spritz the squash slices with cooking spray, then sprinkle a pinch of seasoning over them.
Repeat the layering and compressing in this manner, starting with the potatoes and continuing until the layers reach the top of the pan.
You should use all of the potatoes and onion, but may have some squash left. Spritz the top with cooking spray, then sprinkle a bit more seasoning over the top.
Cover with foil and bake for one hour 15 minutes. Uncover and bake for another 30 minutes, or until the top is lightly browned, the sides have pulled away from the pan and a knife inserted at the centre passes easily through the vegetables to the bottom.
Remove the sides of the pan and let cool for five minutes before cutting into wedges.