Crush saffron threads into powder using a mortar and pestle.

Divide the saffron powder into two portions.

Add warm water to one portion of saffron powder and stir; set aside.

Leave the other portion of saffron powder in powdered form; set aside.

Halve leeks, thinly slice into half-moon shapes, and wash thoroughly.

Pat the sliced leeks dry.

Chop herbs finely and set aside.

Heat olive oil in a large frying pan over medium heat.

Add leeks to the hot oil and sauté for about 5-7 minutes, until they begin to wilt but do not brown.

Increase heat to medium-high and add shrimp and saffron water.

Sauté until the shrimp shells turn pink, about 3-4 minutes.

Add chopped herbs and gently stir to combine.

Remove the pan from the stove and set aside.

Place a small saucepan or frying pan on high heat and add butter.

As soon as butter begins to melt, add the reserved powdered saffron, stir, and pour this saffron-butter over the shrimp.

Gently stir to combine the saffron-butter with the shrimp.

Sprinkle sea salt on top and serve immediately.