Pulse the fresh broccoli in a food processor until it resembles rice-sized pieces—this should take just a few pulses to avoid over-processing into a paste. While the broccoli processes, slice the green onions into thin 1/8-inch rounds and roughly chop the fresh parsley. Open the tuna can and drain it well, pressing gently to remove excess liquid without breaking apart the flakes.

In a large bowl, whisk together the mayonnaise, mustard, and fresh lemon juice until smooth and well combined—this creates a cohesive dressing base. Add the drained tuna, broccoli rice from Step 1, sliced green onions, chopped parsley, and sunflower seeds. Fold everything together gently with a spatula or wooden spoon, being careful not to break up the tuna too much. I like to fold rather than stir vigorously so the tuna stays in nice chunks and feels more substantial. Season with salt and pepper to taste, starting with a pinch of each and adjusting as needed.

Divide the salad among plates or serving dishes. This salad works beautifully served as-is on a bed of greens, spooned into a whole grain wrap, or piled onto toasted bread for a hearty sandwich. I recommend serving it immediately while the broccoli rice maintains its slight crunch—it will soften as it sits.