Cook your salmon. If grilling, brush with olive oil, sprinkle with salt & pepper and cook about 5-7 minutes per side. If cooking in the broiler, place on a sheet pan covered in tin foil, top with salt and pepper and broil for about 10 minutes unless very thick. The rule of thumb with fish is to cook it 10 minutes for every inch of thickness. I will typically add the salmon while it's still hot, but you can cool it to room temperature or cook ahead and leave in the fridge and add cold. Your preference.

Place the celery, onion, dill, olive oil and vinegar into a bowl and toss. Use your fingers to break the salmon into bite sized pieces and add those to the bowl. Mix well, add salt and pepper to taste and serve.