Yep, Heart gets rubbery if cooked too much. The way I cooked mine the other night was great. I put a big scoop of butter in the pan along with sliced onions and let them saute until they started softening up a bit, the I added the slices of heart, about 1/4 inch thick along with mushrooms and maybe 1/3 cup of red wine. I let that cook for about 8 minutes on med high and then added some chopped garlic and a bit of fresh ground pepper. Sauteed it for another 8 minutes or so, until the meat was just pink inside. The wine and butter kind of makes a nice sauce in the bottom of the pan, dont throw that out. I put it on a couple of slices of Italian bread, it was fantastic. Had the leftovers cold last night too. Mmmmmm. Gotta go get another deer so I can have that again!