Preheat the oven to 425°F (220°C). Place 1 large sheet pan in the oven while it heats.

Break the cauliflower into tiny florets, including the leaves. Transfer it to the hot sheet pan.

Add 3 tbsp olive oil, paprika, garlic powder, cumin, and 1/2 tsp salt. Toss until the cauliflower is evenly coated.

Roast the cauliflower for 30 minutes. Toss it halfway through roasting.

Rinse, drain, and pat the cannellini beans completely dry. Roughly chop the beans.

Place the beans on the second sheet pan. Add 1 tbsp olive oil, dried basil or oregano, 1/2 tsp salt, and black pepper.

Toss the beans to coat them with the seasonings. Roast for 15 to 20 minutes until browned and crisp at the edges.

Cool the roasted beans for 5 minutes. Toss them with 1/2 cup arugula and pistachios.

Add 2 tbsp olive oil, tahini, lemon juice, maple syrup, scallions, 1 tsp salt, black pepper, and 1 tbsp water to a jar.

Whisk or shake the dressing until smooth. Add the remaining water, 1 tsp at a time, if a thinner dressing is desired.

Remove the roasted cauliflower from the oven. Add 2 cups arugula and the red onion to the sheet pan.

Toss the warm cauliflower mixture gently. Transfer it to a serving platter or bowl.

Top the cauliflower salad with the crispy bean crumble. Drizzle with dressing to taste.

Toss the salad just before serving. Reserve any unused dressing separately.