Clean all exterior fat, internal vascular structure and silver skin
from the heart. After cleaning the heart you should have about 1 pound of clean, red muscle. The meat should look similar in color and texture to beef tenderloin
Combine the orange juice
, wine, olive oil, vinegar, 2 teaspoons salt, 1 teaspoon pepper, chili flakes, thyme and garlic in a container with a cover. Separation is natural. Marinate the heart, covered, in the refrigerator for 2 hours.
Remove the heart from the marinade
and pat dry. Sprinkle with salt and pepper. Warm a pan with the extra-virgin olive oil to high heat. When the pan is very hot, sear
the heart 1 to 2 minutes per side. Be careful not to overcook, serve rare to mid-rare. Remove from the heat and let rest for 1 minute. Slice thin and serve with some Marrow
Butter over Roasted Broccoli and Anchovy.