Preheat the oven to 450. Leave the potatoes unpeeled (or peel them if you want, you're the chef) but slice them into disks. Line a baking sheet with foil or parchment unless you love cleaning baking sheets. Toss the potatoes with 2 tbsp of olive oil and season well with salt and pepper. Roast for 20 minutes until tender.
While the potatoes are cooking, mix the vinaigrette for the salmon. Add the capers, grainy mustard, balsamic, and olive oil in a small dish until combined. Season with a little salt and pepper.
Once the potatoes are out of the oven, line another baking sheet with foil or parchment and drizzle the salmon with half the caper vinaigrette. Season with salt and pepper. Roast in the hot oven for ten minutes, turning once halfway.
Toss the potatoes, chickpeas, mozzarella cheese, avocado, and greens in a bowl. Mix the salad dressing ingredients in another bowl: mustard, apricot jam, balsamic, and 3 tbsp olive oil. Pour it all over the salad mix gently. Season the salad with salt and pepper to taste.
Drizzle the rest of the caper vinaigrette over the salmon and serve alongside the salad. Voila.