Preheat the oven to 425F convection (or 450F regular). Line a baking sheet with parchment paper.
Add the cauliflower to the baking sheet. In a medium bowl, mix together 2 tablespoons oil and tomato paste. Pour over the cauliflower along with 1 teaspoon salt, ½ teaspoon pepper, and red pepper flakes (if using). Use your hands to toss to coat and rub the oil/tomato mixture into the cauliflower. We’ll use that same bowl to make the yogurt mixture.
Bake for 20 minutes or until the cauliflower is charred. Scatter the dates onto the baking sheet and bake for 5 more minutes. Add the parsley to the baking sheet and toss to mix everything together.
Meanwhile, in a large skillet over medium-high heat, warm the remaining 1 tablespoon olive oil. Once the oil is hot and shimmering, add the beef, sprinkle with ¼ teaspoon salt, break into chunks and let it cook, undisturbed for 2-4 minutes or until nicely browned. Continue to break into smaller chunks and cook until cooked through. Add the spices, remaining ½ teaspoon pepper, and stir for just 15 seconds to toast the spices. Remove from heat and stir in the soy sauce.
In the medium bowl, add the yogurt, lemon, and remaining ¼ teaspoon salt and stir to combine.
Serve the beef over the cauliflower. Top with the yogurt, cucumber, nuts, and generous squeeze of lemon. Serve with bread or another starchy base, if desired.