In a mini-food processor or a blender, add the egg yolks, mustard, salt, pepper and lemon juice.   Process for 30 seconds.

In a small saucepan set over medium heat, add the butter and heat slowly until it is melted and just begins to foam. Transfer the melted butter to a small pitcher or pourable container.

With the processor running, slowly, drizzle the melted butter through the lid opening into the egg mixture. Continue processing and drizzling until all the butter has been incorporated. About 3 minutes. The egg mixture will begin to emulsify and thicken. If it becomes thicker than you like, thin with a tablespoon or more of hot water (or lemon juice) to the desired consistency. Stop the motor, taste and adjust salt and pepper if needed, and whiz again for a second or two.

Transfer the hollandaise sauce into a small dish and stir in the snipped dill. Set the dish in a shallow pan of hot tap water to keep warm. 

Pat the fillets dry with paper towels to remove as much moisture as possible. Brush the salmon flesh lightly with olive oil and season with salt and pepper.

Heat a non-stick skillet over medium-high heat and add the olive oil (use enough oil to coat the bottom of the skillet) and heat until the oil is hot.  

Place the salmon fillets, flesh side down, in the skillet and press gently with a spatula.  Reduce the heat to medium and cook the fish for 4 minutes.  

Flip the salmon fillets to the skin side and cook for another 1 or 2 minutes for medium-rare.  Transfer to a platter for serving.

Place a portion of black rice in the center of each serving and add a salmon fillet.  Top each salmon fillet with a portion of the dill hollandaise sauce and garnish with a sprig of dill.