Prep the cauliflower: Trim the outer leaves, leaving some tender ones if you like. Trim the base so it sits flat, but keep the core intact so the head holds together.
Rinse and pat very dry.
Oil and season: Rub the cauliflower with olive oil. Sprinkle with 1 to 1.5 teaspoons salt and plenty of black pepper, getting into crevices.
Make the spiced garlic butter: In a small bowl, mix softened butter, garlic, smoked paprika, cumin, chili powder, coriander, turmeric, lemon zest, and lemon juice. Stir in half the herbs.
Taste and adjust salt and chili.
Set up your smoker or grill: Preheat to 300–325°F (150–165°C). Add a handful of soaked wood chips to the smoker box or wrap them in foil with holes and place over heat on a gas grill. For charcoal, toss chips directly onto hot coals.
Smoke the cauliflower: Place the cauliflower on the cooler side of the grill or smoker, stem side down.
Close the lid and smoke for 60–90 minutes, until a skewer slides in with gentle resistance. Rotate halfway for even color. Add chips as needed for steady smoke.
Baste with spiced butter: During the last 20–25 minutes, brush the cauliflower generously with the spiced garlic butter, letting it melt and cling to the florets.
Save some for serving.
Finish for color (optional): If you want more char, move the cauliflower briefly over direct heat or into a 425°F oven for 5–10 minutes. Watch closely to avoid burning the garlic.
Rest and garnish: Let the cauliflower rest for 5–10 minutes. Brush with more butter, sprinkle with remaining herbs, and add a squeeze of lemon.
Slice into wedges or break into florets.
Serve: Finish with a pinch of flaky salt. Great with tahini or yogurt on the side, or spooned over couscous, lentils, or grilled flatbreads.