Preheat the oven to 375°F.
Put the cauliflower top-down on a cutting board. Remove all the rough green bottom stems and cut out the rough bottom stem core. Flip it over and place on a baking sheet.
Drizzle the cauliflower with a liberal amount of olive oil and rub to coat it. Sprinkle with salt. Cover the cauliflower with foil and roast for 30 minutes. Uncover and roast another 35-45 minutes, or until the cauliflower is a deep golden brown on top.
While the cauliflower is roasting, prepare the tahini drizzle. Add the tahini, parsley, red pepper, garlic, lemon juice and water to a blender. Add a pinch of salt and blend until smooth, but still with a few flecks of green throughout. Add more water as needed to get to a "drizzly" texture. Season with salt as needed.
To make the feta and date salad, grab a large bowl. Toss in the sliced peas, radishes, basil, mint, dates and feta. Toss to combine and add a squeeze of lemon juice, the sumac and a large pinch of salt. Drizzle with a bit of olive oil and taste. Add lemon juice and salt as you prefer. Set aside.
When the cauliflower is out of the oven, pour the tahini drizzle right on top. Slice it into 4 large pieces and add each to their own bowl. Pile a large serving of the feta & date salad next to each. Enjoy as soon as you can!