Preheat your oven to 180C.
Halve your new potatoes and toss them in olive oil, season well and roast for about 20 minutes.
Now for the eggs and the gribiche sauce... Whilst the potatoes are roasting, boil your eggs for 7 minutes. Once 7 minutes is up, run the cold tap on the pan to stop them cooking. Peel and set them aside, apart from one. Halve and scoop out the yolk. Mash the yolk (using a fork or a pestle and mortar) with a little oil to make a smooth paste. Then very slowly, drizzle in about 4 tablespoons of oil. Whisk so you have a smooth emulsion, adding the mustard and vinegar. Now make the sauce a little thinner by adding two more tablespoons of oil. And finally season and add the herbs. Taste and adjust accordingly if you like.
At about 20 minutes, when they are not far off, add the broccoli. Drizzle oil on the broccoli too. Roast for about 10 minutes - keep an eye on them so check they're not burning as the florets are very delicate. Turn your oven down if they are roasting too aggressively!
Once the broccoli and potatoes are pretty much done, pop your salmon fillets on top and roast for 10 minutes.
When the salmon is cooked, take out the traybake and remove them from the pan. Toss the vegetables in most of the sauce along with the rest of the quartered eggs, and then top with the salmon again. Dribble the remaining sauce over the salmon and sprinkle more herbs on top.