Step 1

Preheat the oven to 425°F (220°C). Spread the cauliflower on a baking sheet in a single layer. Drizzle with the oil, season generously with salt and pepper, and toss to coat. Roast the cauliflower, tossing the florets halfway through, until they are deep golden and crispy, 30 to 35 minutes total.

Step 2

While the cauliflower is roasting, use a vegetable peeler to peel 3 strips of zest from the lemon. Cut each strip crosswise into very thin slices. Cut the lemon in half, reserving one half and storing the other for another use.

Step 3

Transfer the roasted cauliflower to a serving bowl. Top it with the parsley, capers, jalapeño, and sliced lemon zest. Squeeze the mixture with the lemon half and drizzle it with more oil. Toss to coat all of the ingredients, and sprinkle with a pinch or two of the flaky salt.