Cut all vegetables into uniform 1-inch pieces—this ensures even cooking and creates an appealing presentation. Cut the cauliflower into florets, the beetroot and pumpkin into cubes, the carrot into chunks, the red onion into wedges, and the zucchini into rounds. In a large bowl, toss all prepared vegetables with the extra virgin olive oil, salt, coriander, and black pepper until evenly coated. The coriander adds an authentic Middle Eastern warmth to the vegetables, and coating them now allows the flavors to meld as they roast.

Preheat your oven to 400°F/200°C (I find this temperature slightly higher than traditional recipes gives better caramelization and deeper flavor). Spread the seasoned vegetables from Step 1 in a single layer on a baking tray, making sure pieces aren't crowded—this allows them to roast rather than steam. Roast for 30-40 minutes, stirring halfway through cooking to ensure even browning. The vegetables are done when the edges are caramelized and golden, and a fork easily pierces the largest pieces.

While the vegetables roast, whisk together the tahini, minced garlic, and lemon juice in a bowl until combined. Tahini can be thick, so gradually add water a tablespoon at a time, whisking after each addition, until the sauce reaches a honey-like consistency that will drizzle smoothly over the vegetables. Taste and adjust seasoning with the remaining salt and black pepper. The tahini sauce should be creamy but pourable—not too thick or it won't coat the vegetables properly.

Arrange the roasted vegetables from Step 2 on a serving platter or individual plates. Drizzle generously with the tahini sauce from Step 3, then sprinkle the toasted pine nuts and za'atar spice mix over the top. The za'atar adds a bright, tangy finish that complements the earthiness of the roasted vegetables and richness of the tahini.