Clean mushrooms by wiping with a damp cloth or very briefly rinsing and patting dry. If mushrooms are large, halve or quarter them so pieces are roughly uniform (about 2–3 cm). Peel and cut the red onion into 1 cm thick wedges or large slices so they grill without falling apart. Peel and mince the garlic.

Season

Place the mushrooms and onion wedges in a bowl. Add 2 tbs extra-virgin olive oil, minced garlic, 1 tsp salt and 1/2 tsp freshly ground black pepper. Toss gently so all pieces are evenly coated. Let sit 10 minutes to absorb flavors.

Grill or roast

Preheat a grill or grill pan to medium-high (about 200–220°C / 400–430°F) or preheat oven to 220°C (430°F) and line a baking sheet. Brush the grill grates or baking sheet with 1 tbs olive oil. Arrange mushrooms and onion slices in a single layer without overcrowding. Grill 4–6 minutes per side until well browned and slightly charred at the edges, or roast in the oven 18–22 minutes, turning once, until caramelized and tender. Remove to a serving plate and sprinkle with 2 tbs chopped cilantro; keep warm.

Cauliflower Dressing

Cook cauliflower

Bring a small pot of salted water to a boil. Add the cauliflower florets and blanch for 6–8 minutes until very tender (or steam for 8–10 minutes). Drain thoroughly and transfer to a blender or food processor. Alternatively, roast cauliflower (220°C/430°F for 18–20 minutes) for a nuttier flavor before blending.

Blend dressing

To the warm cauliflower in the blender add 1/2 cup Greek yogurt, 2 tbs fresh lemon juice, 1 tsp olive oil, 1/2 tsp ground cumin, 1/4 tsp smoked paprika, 1/2 tsp salt, 1/4 tsp black pepper, and 2 minced garlic cloves (if you prefer a stronger garlic note). Blend until completely smooth and creamy, about 1–2 minutes, scraping down sides as needed. Taste and adjust seasoning; add 1/2 tsp honey or agave if you want to temper acidity, or a splash of water (1–2 tbs) to loosen consistency. The dressing should be thick but pourable.

Finishing & Assembly

Plate the dish by spooning a generous layer of cauliflower dressing onto a serving platter or individual plates (about 1–2 tbs per serving). Arrange the warm grilled mushrooms and onion wedges on top of the dressing in an even layer.

Garnish with 2 tbs fresh cilantro leaves scattered over the mushrooms. Drizzle a little extra-virgin olive oil (about 1 tbs) over the top and finish with a squeeze of lemon from the wedges if desired. Serve warm or at room temperature.

Storage: Leftover dressing keeps in an airtight container in the refrigerator for up to 4 days. Grilled mushrooms are best eaten within 2 days; reheat gently in a skillet or oven to retain texture.