Place water, black beans, onion, ham bouillon, and bay leaf in a pressure cooker. Close cooker securely and bring to high pressure according to manufacturer's instructions. Cook for 15 minutes after steam starts to escape. Remove from heat and allow cooker to release pressure naturally.
Heat olive oil in a skillet over low heat. Add garlic; cook and stir until golden, about 1 minute. Stir oil and garlic into beans. Remove bay leaf and season beans with salt.