Why have just one type of potato when you can have two?

After all, the holidays were made for going big on excess.

Even so, I’m sure I’m not alone in trying to shave a calorie or two here and there wherever it won’t be missed.

So, while I swoon over decadent scalloped potatoes with all that heavy cream and oodles of cheese, sometimes it’s a bit much even for me.

That’s why I was thrilled to discover “2-Scalloped Potatoes with Chimichurri,” a dazzling spiral of Yukon Gold and sweet potato slices cooked not with cream, but chicken or vegetable stock instead that gets finished with a drizzle of bright, garlicky Argentinian chimichurri sauce.

The recipe is from the new “Ottolenghi Test Kitchen: Extra Good Things” (Clarkson Potter), of which I received a review copy.

It’s the newest Ottolenghi Test Kitchen cookbook by Noor Murad and Yotam Ottolenghi. The latter, of course, is the acclaimed London restaurateur and best-selling cookbook author; and the former is the head of his Ottolenghi Test Kitchen.

This collection of recipes demonstrates how homemade sauces, dressings, and condiments can add a spark to make dishes extra special. The recipes for the most part are vegetable-forward, but there are also a few meat-based ones included, such as one for livening up store-bought rotisserie chicken with a flavorful blue cheese dressing.

Learn how to cure egg yolks with sea salt and sugar, then use them to garnish creamed spinach with paprika and pine nuts. Whip up a tahini-Parmesan dressing to boost a simple endive salad with maple walnuts. And make a batch of hazelnut praline to take a devil’s food cake to a whole new level.

In this particular dish, Yukon Gold and sweet potatoes are cut thinly, seasoned with olive oil, oregano, parsley, and garlic, then overlapped in a concentric circle inside a cast-iron pan. Stock gets poured over the potatoes before the pan is slid into a hot oven.

The chimichurri is simply more chopped parsley, oregano, and garlic stirred together with more olive oil, plus a splash of red wine vinegar, and a bit of minced Fresno chile. A jalapeno will work in a pinch instead, too. The chimichurri gets spooned over in dollops just before serving.

It all makes for a dramatic looking dish sure to prompt plenty of “oohs” and “ahhs” when brought to the table. Full of vivid colors, it’s a dish that looks like it took a lot of effort when the only task that took any real time was slicing the potatoes.

The potato slices bake up tender and creamy — without any cream. In contrast, the edges all over the top get crispy. You get the sweet of the sweet potatoes with the more starchy, neutral Yukon Golds to offer up two distinct tastes in one. The chimichurri adds a big punch of garlic and herbs to turn mild-mannered potatoes into a super peppy dish.

It’s everything you want in a potato dish for the holidays — just lightened up a bit.

2-Scalloped Potatoes with Chimichurri

(Serves 6, as a side)

1 3/4 pounds Yukon Gold potatoes

1 pound 5 ounces sweet potatoes

1/4 cup oregano leaves, roughly chopped

1/4 cup parsley, roughly chopped

4 garlic cloves, peeled and minced

5 tablespoons olive oil, plus extra for greasing

1 cup chicken or vegetable stock

Salt and black pepper

For the chimichurri:

1/2 cup parsley, finely chopped

1/4 cup oregano leaves, finely chopped

1 garlic clove, peeled and finely chopped

1 Fresno chile, finely chopped, seeds and all (1 tablespoon)

2 tablespoons red wine vinegar

1/4 cup olive oil

Preheat oven to 400 degrees.

Peel the potatoes. Use a mandolin to slice the Yukon Gold potatoes into paper thin rounds. Adjust the mandolin and slice the sweet potatoes twice as thick, so about 1/16-inch thick. Alternately, slice the potatoes by hand. Place the slices in a large mixing bowl and add the herbs, garlic, 3 tablespoons of oil, 1 1/2 teaspoons of salt, and a good grind of pepper and toss gently to combine, being careful not to break apart the potatoes.

Lightly grease a large, ovenproof cast-iron frying pan or a round baking dish with a 9-inch-diameter bottom. Starting from the edges of the pan, arrange the potatoes in a concentric circle, alternating between a few Yukon Gold and a few sweet potatoes (this doesn’t have to be perfect). It should look like a swirly flower by the end. Pour the stock evenly over the potatoes. Lightly grease a piece of foil, then cover the pan or dish tightly with the foil, greased side down, and bake for 35 minutes. Remove from the oven, then turn the heat up to 450 degrees and remove the foil. Drizzle with the remaining 2 tablespoons of oil and bake for 20 minutes, or until nicely browned on top. Set aside to cool slightly, about 15 minutes.

Meanwhile, make the chimichurri. Put all the ingredients plus 1/4 teaspoon of salt and a good grind of pepper into a small bowl and mix well to combine.

When ready to serve, spoon half the chimichurri all over the potatoes and serve the rest in a bowl alongside.

Note: Any leftover chimichurri can be stored in a sealed container in the fridge for up to 3 days.

From “Ottolenghi Test Kitchen: Extra Good Things” by Noor Murad and Yotam Ottolenghi

Another Ottolenghi Test Kitchen Recipe to Enjoy: Chickpeas Cacio e Pepe

And Another: Butternut Squash with Orange Oil and Caramelized Honey

Plus More Ottolenghi Recipes: Miso Butter Onions

And: Roasted Eggplant with Anchovies and Oregano

And: Squash with Chile Yogurt and Cilantro Sauce

And: Vineyard Cake