How to Make Seafood Stock at Home | Eater

"Led by chef Renee Toupounce, this Mystic restaurant emphasizes using whole fish and minimizing waste, utilizing heads, tails and bones to build a delicate, focused seafood stock. Toupounce advises avoiding strong-flavored vegetables and herbs (skip carrots, sage, rosemary) and instead using softer aromatics like white onion, celery or fennel and light herbs so the true flavor of the fish can come through. She also stresses gentle, low-and-slow simmering rather than a rapid boil to prevent bitterness, and notes that in a restaurant setting cooks must be mindful of shellfish–finfish combinations because of allergy concerns." - Tanya Edwards