Rub the salmon with 2 teaspoons of olive oil, 1/3 teaspoon of salt and a good grind of pepper. Set aside while you make the salsa.
Place a large skillet and place on high heat, and add 1/2 cup olive oil. Add the celery and pine nuts and fry for 4–5 minutes, frequently stirring, until the nuts begin to brown (don’t take your eyes off them, as they can easily burn).
Remove the pan from the heat and stir in the capers and their brine, olives, saffron and its water, and a pinch of salt. Drain the currants and add these, along with the parsley, mint, lemon zest, lemon juice, and a splash of vinegar. Set aside.
Preheat oven to 350°F. Place another large skillet over medium-high heat and, when hot, add 1 tablespoon olive oil. Add the salmon fillets, skinned side up, and fry for 3 minutes until golden brown. Flip the fillets over and continue to fry for 1 minute, then place the pan in the oven for 4-5 minutes until salmon is done to your liking.
Arrange the salmon on four plates and spoon the salsa over it. If you have any celery leaves reserved, scatter these on top.