By CHRISTOPHER KIMBALL Christopher Kimball’s Milk Street

Sweet and sour in Italian cooking, or agrodolce, has roots that predate the Romans, but credit Sicily – and the North African influence on their cuisine – with keeping it alive.

Sicilians slather a basic mixture of vinegar and honey on grilled meat and fish. They turn roasted eggplant into caponata with a version of it dressed up with alliums, raisins and herbs. And sometimes they add nuts and chilies for a textured condiment that hits most, if not all, of the notes on the flavor spectrum.

The latter is what we had in mind for this acorn squash in our book “Cook What You Have,” which draws on pantry staples to assemble easy weeknight meals. It couldn’t be easier to prepare and will make a perfect vegetarian side dish for Thanksgiving.

As the sliced squash roasts in the oven – you don’t even need to peel it – we build a tangy-sweet sauce with olive oil, balsamic vinegar, honey, Dijon mustard, rosemary, red pepper flakes and raisins. The mustard, though unconventional, adds an extra sharpness to balance the honey and natural sweetness of the nutty vegetable.

Once the squash is nearly cooked, we finish it with the agrodolce mixture so it takes on a glaze-like luster in the oven. Waiting to add toasted almonds as a garnish retains their crispness for textural contrast to the velvety squash.

Acorn squash is ideal for this recipe because the skin is edible (or easily peeled off after roasting if you prefer). Butternut squash also works, but it will need to be peeled.

Agrodolce acorn squash

Start to finish: 1 hour

Servings: 4 to 6

1½ – to 2-pound acorn squash, halved lengthwise, seeded and sliced into 1inch-thick half rings

4 tablespoons extra-virgin olive oil, divided

Kosher salt and ground black pepper

½ cup balsamic vinegar OR cider vinegar

2 tablespoons honey

2 tablespoons Dijon mustard

1 teaspoon dried rosemary OR dried thyme

½ teaspoon red pepper flakes

¼ cup raisins ¼ cup whole almonds, roughly chopped OR slivered almonds OR sliced almonds, toasted

Heat the oven to 475° F with a rack in the middle position. On a rimmed baking sheet, drizzle the squash with 1 tablespoon oil and sprinkle with ½ teaspoon salt and ¼ teaspoon black pepper. Toss until well coated, then distribute in an even layer. Roast until the squash is browned on both sides and a skewer inserted into a piece meets no resistance, 25 to 30 minutes.

Meanwhile, in a small bowl, whisk together the remaining 3 tablespoons oil, the vinegar, honey, mustard, rosemary and pepper flakes, then stir in the raisins.

When the squash is done, remove the baking sheet from the oven. Pour the vinegar-raisin mixture onto the squash, distributing the raisins evenly, then roast until the liquid is bubbling and syrupy, 5 to 7 minutes.

Using a wide metal spatula, transfer the squash to a platter. Drizzle with the glaze from the baking sheet and sprinkle with the almonds.

Optional garnish: Fresh flat-leaf parsley or pomegranate seeds or both