In “One Good Meal,” we ask cooking-inclined creative people, who aren’t professional chefs, to share the story behind a favorite dish they actually make and eat at home on a regular basis — and not just when they’re trying to impress.

It all started with a trip to Puglia. This was maybe a decade ago, and Rosie Assoulin didn’t go herself. But her in-laws did, and they came back raving about a meal they’d eaten: a whole white fish, baked and served over crispy vegetables. So simple, so Italian. Assoulin, 32, and her husband Max decided they’d try to replicate the dish through a process of experimentation — and they quickly found it to be “one of those home-cooked recipes where you just kind of wing it and it’s always different every time.” Branzino makes an ideal fish, they discovered, though snapper and bass work too. Cauliflower is nice as one of the vegetables. Eggplant, if they have it. The constant: They always put herbs (thyme, rosemary) and lemon into the fish’s cavity — “sometimes we’ll put lavender in if we’re feeling a little fancy” — before baking it in a cast-iron tray, the kind you might use to cook paella. They bring that pan to the table and eat straight out of it.

Assoulin’s clothes have that same joyful, improvisational feel. When her fall/winter 2018 collection showed recently at New York Fashion Week, one model wore an electric-blue wide-lapel pantsuit with bell-bottom trousers and an untucked shirt the color of Sunkist. Assoulin, who won the CFDA emerging designer award in 2015, stays busy these days dressing the likes of Amal Clooney and Ruth Negga — a schedule that makes her thrown-together fish dish a regular one on weeknights. It’s become a staple in her TriBeCa apartment, a proper dinner she and Max can pull together in under an hour and enjoy after their three kids have gone to bed, or scale up and serve at their frequent Mediterranean-style dinner parties, one fish per guest. As for the in-laws? “They’re not married anymore,” Assoulin says, “but we still make it for them all the time.”

Rosie’s White Fish With Vegetables

∙ 2 branzino or red snapper (make sure eyes are clear, not cloudy) cleaned and scaled, slit up the belly

∙ 1 handful herbs (torn thyme and rosemary sprigs)

∙ 1 lemon, sliced thin

∙ 1 pound Yukon fingerling potatoes, sliced thin

∙ 1 yellow squash, sliced thin

∙ 1 green zucchini, sliced thin

∙ 2 handfuls of cherry tomatoes, halved lengthwise

∙ 2 handfuls of whole Kalamata olives (pits in)

∙ 2 tablespoons capers

∙ 5 whole garlic cloves (with skin)

∙ Paprika to taste

∙ Garlic powder to taste

∙ Salt to taste

∙ Aleppo pepper to taste

∙ Olive oil to taste

1. Preheat the oven to 420 degrees. While it heats, stuff the fish with lemon and herbs.

2. Massage sliced vegetables, olives and capers together with garlic until well combined.

3. Place fish atop vegetables in a cast-iron skillet or baking tray. Drizzle everything with olive oil and spices. Do not crowd the pan; it’s better to divide the ingredients into two trays.

4. Roast until fish is flaky and vegetables are crispy, about 40 minutes. Makes 2 servings.