Rinse broccoli rabe well, and steam just until tender but still bright green, about 3 to 4 minutes. Rinse in a colander beneath cold running water. Drain well, and wrap in a clean tea towel to absorb excess water. Chop into small pieces.

Cut broccoli florets from stems, and then cut into small (1/2-inch) pieces. Steam just until tender but still bright green, about 3 to 4 minutes. Rinse in a colander beneath cold running water. Drain well, and wrap in a clean tea towel to absorb excess water.

Place rabe and broccoli florets in a large bowl with raisins and cashews. Whisk together the oils, vinegar, garlic, and cayenne. Drizzle over salad, and lightly toss. Sprinkle with toasted sesame seeds. Serve at room temperature or chilled.