Salmon Niçoise Salad

Ingredients

• 1 red onion (medium, halved and thinly sliced)
• 2 tablespoons apple cider vinegar (or red wine vinegar)
• ¼ teaspoon salt
• 2 tablespoons olive oil
• ½ teaspoon Dijon mustard
• 1 teaspoon honey (can be omitted)
• 1 sweet potato (medium, peeled and cut into cubes)
• 1 bunch of asparagus (about 10-12 spears)
• 2 eggs (large)
• 3 cups arugula (aka rocket, baby spinach, or watercress leaves)
• 7-8 oz hot-smoked salmon (250 grams, or fresh salmon fillets)
• 20 Spanish/black olives
• Salt and Pepper to taste
• 1 tablespoon lemon juice (to drizzle, optional)