Pour the olive oil into a wide, high-sided saute pan.

Add the leeks, onions, and garlic to the pan.

Saute over medium heat until the vegetables are soft but not colored.

Add the Fish Fumet to the pan and bring to a boil.

Reduce the heat to a bare simmer.

Season the black bass fillets with salt and pepper.

Place the seasoned fillets into the poaching liquid, skin-side up.

Ensure the liquid comes about halfway up the fish fillets.

Using a spoon, baste the tops of the fillets with the Fish Fumet as they cook.

Continue basting as the fillets begin to curl, keeping the broth evenly coating the skin.

Cook in this manner, basting continuously, for 4 to 5 minutes, or until the skin pulls away from the fillets easily.

Remove the fillets from the liquid and divide among 4 warmed bowls.

Keep the Fish Fumet and aromatics simmering on the stove.

Add the mint leaves and chives to the Fish Fumet.

Squeeze in the lemon juice, and add the best-quality olive oil; swirl to blend.

Check the seasonings and adjust if needed.

Spoon the Fish Fumet over the fillets, making sure each bowl has vegetables and herbs.

To make the Fish Fumet: Place the black bass bones, water, wine, celery stalks, garlic clove, onion halves, and leek into a stockpot over high heat.

Bring the mixture to a boil, reduce the heat, and simmer for 45 minutes.

Strain the fumet through a fine-mesh sieve.