Blanch the broccoli in boiling water for 8 minutes, adding the chopped red pepper for the last minute. Drain both and refresh in cold water. Drain.
Grill the salmon fillet for 6-8 minutes on either side. Leave to cool before breaking into large flakes. To make the dressing place the parsley, pumpkin seeds, garlic, Parmesan, lemon juice and olive oil in a small blender and blend until smooth. Toss the broccoli, red pepper and salmon gently in the dressing.
Divide the watercress between four plates then soon over the dressed vegetables and salmon.