@NinMD Wash, pick off any veins or connective stuff. I didn’t find much of anything. Cover with water in a sauce pan and bring to a simmer. I added 1/4 of a lemon, squeezed and put the rind in. Add salt and simmer about 10 minutes. Drain and use as you wish. Some people also grind it and fry it. Lots of recipes from around the world for brain. India, SE Asia, Spain, Latin America etc.
I fried mine in bacon grease with golden brown onion, jalapeño, tomato, cilantro and garlic powder towards the end. S&P and squeeze some lemon over it.