Mix together the crème fraîche, dill, and lemon juice in a small bowl. Set aside.
Brush a little olive oil over the salmon pieces and then season with salt and pepper
Heat a large skillet over medium-high heat.
Add the ghee to the skillet. When the ghee is hot, add the salmon, flesh side down. Let the salmon cook for 3 to 4 minutes without moving so it can brown. You’ll notice the edges of the salmon becoming golden brown and the flesh closest to the bottom of the pan turning opaque.
Then, flip the salmon over to be skin side down and let cook for another 3 to 4 minutes; cook longer for a thicker piece of salmon. Most fish cook through in about 10 minutes for every inch of thickness.
Once the salmon is done, transfer to plates.
Fold the sliced cucumber into the crème fraîche mixture and season to taste with salt and pepper.
Top the salmon with dollops of the cucumber mixture and serve.