Preheat oven to 400 degrees F.
Toss cauliflower with olive oil and salt. Spread on large baking sheet, being sure not too crowd.
Roast for 35 minutes, stirring once, until cauliflower is golden brown.
While cauliflower is roasting, whisk together peanut butter, water, vinegar, lime juice, red pepper flakes, and 1/4 teaspoon salt.
Remove cauliflower from oven, and put on a platter. Sprinkle with prunes, cilantro, and crushed peanuts. Drizzle with peanut sauce. Give entire dish a big squeeze of lime juice all over top. Serve.