It's not good to feed them terrestrial based meat products other then bugs I guess. Beef heart and chicken are not good for fish. I believe that meat pie is designed for reptiles like monitors. I'd stick with another grub pie or a veg based one. Most of what Oscars eat in the wild have vegetable matter in their gut contents.
There are two versions of Meat Pie, one for reptiles and one for fish.
Fish ingredients;
INGREDIENTS: Whole Sardine Meal, Whole Squid Meal, Whole Krill Meal, Pea Protein Isolate, Dried Brewers Yeast, Carrageenan Algae, Konjac, Carob Bean Gum, Dried Kelp, Potassium Citrate, Calcium Propionate, Dicalcium Phosphate,Taurine, Spirulina Algae, Phaffia Rhodozyma Yeast, Paprika Extract, Calendula Flower Powder, Marigold Flower Extract, Rose Hips Powder, Turmeric Root Powder, Malic Acid, Sodium Chloride, Canthaxanthin, Potassium Sorbate, Magnesium Gluconate, Lecithin, Rosemary Extract and Mixed Tocopherols (as preservatives), Vitamins (Vitamin A Supplement, Vitamin D Supplement, Choline Chloride, Ascorbic Acid, Vitamin E Supplement, Niacin, Beta Carotene, Pantothenic Acid, Riboflavin, Pyridoxine Hydrochloride, Thiamine Mononitrate, Menadione Sodium Bisulfite Complex, Folic Acid, Biotin, Vitamin B-12 Supplement).