Prepare the citrus: Peel the orange and grapefruit, then segment them by cutting between the membranes. Set aside.

Slice the red onion thinly. If the flavor is too strong, soak the slices in cold water for 5 minutes, then drain.

Toast the almonds in a dry pan over medium heat for 2-3 minutes until fragrant. Let them cool, then chop roughly.

Make the vinaigrette: In a small bowl, whisk together olive oil, honey, apple cider vinegar, Dijon mustard, salt, and pepper.

Assemble the salad: In a large bowl, combine watercress, citrus segments, red onion, and toasted almonds.

Drizzle the vinaigrette over the salad and toss gently to coat. Serve immediately.