Drain tofu and with a tofu press or between paper towels, press tofu to drain liquids. You can even drain the tofu the night before for a firmer texture. In large frying pan heat up olive oil; add diced onion and cook until tender and translucent. Using your hands, crumble the tofu into the pan. Stir in all remaining ingredients, except for spinach, and cook on medium heat until tofu is lightly browned. Stir in spinach and cook until just wilted. Remove from heat and enjoy!