Fungi are a promising functional biomaterial for sustainable, delicious, and nutritious meat alternatives, yet their textural and mechanical suitability to replace steak is under-explored. Here, we investigate three fungi-based steaks: Meati – composed of the mycelium roots of fungi, Omni – made entirely from lion’s mane fruiting body, and Beyond – a blend of mycelium, wheat, and faba bean protein. We performed 150 mechanical tests across tension, compression, and shear for both in-plane and cross-plane fiber directions up to 10% stretch or shear. Using lyophilization, we extracted the water content of each fungi-based steak. Lastly, we conducted sensory tests with n=55 participants in total who ranked 12 mechanical attributes, such as softness and chewiness, for both in-plane and cross-plane directions. To identify the best constitutive model for each steak, we used a 12-term transversely isotropic, incompressible constitutive artificial neural network composed of I1, I2, I4, and I5. With L1 regularization, we found that the best 1- or 2-term models were simply I1 for Beyond, and I1 and exp(I52) for both Meati and Omni, revealing that Beyond is an isotropic material while Meati and Omni have a clear preferred fiber direction. Notably, these simple models demonstrated robust fits to our data, with an average goodness of fit, R2, across all 6 loading modes simultaneously (tension, compression, and shear both in-plane and cross-plane) of 0.94±0.05, 0.76±0.26, and 0.93±0.04 for Beyond, Omni, and Meati, respectively. Beyond had the highest average stiffness at 89.8 kPa and 87.4 kPa, Omni the least stiff at 26.7 kPa and 25.2 kPa, and Meati the middle stiffness at 40.7 kPa and 35.2 kPa, in-plane and cross-plane, respectively. The water content of Beyond, Meati, and Omni was 61%, 68%, and 84%. Mechanical modelling shows significant promise in gradually replacing sensory surveys and accelerating the design of fungi-based steaks that mimic animal steaks.