The key component is the garlic-onion-ginger combo with rice washing and vegetable broth. You can add other vegetables like bok choy, kale, etc. You may veganize it however you like just don't forget the base flavor!
What is rice washing? It's the water you use to wash the rice in. The first rinse is ideal and will impart a nice rice flavor in Tinola. To get rice washing, wash about a cup of rice with water, mix around, then separate the liquid from the rice. Use the wash in the Tinola recipe. To cook the rice, add a new cup of water and cook using a rice cooker.