Using your hands, crumble the block of tempeh into small, fine pieces to mimic the texture of ground meat.
Set it aside.
In a large saucepan or Dutch oven, heat the olive oil over medium heat.
Add the finely chopped onion and cook, stirring frequently, for 5-7 minutes until it becomes soft and golden.
Stir in the minced garlic and cook for another 30 seconds until fragrant.
Add the crumbled tempeh, 1 cup (240 ml) of water, and the soy sauce or tamari to the saucepan.
Bring the mixture to a boil, then reduce the heat to low, cover, and simmer for 5 minutes.
Remove the cover and continue to simmer, allowing the liquid to evaporate until the tempeh begins to sizzle in the pan. This step is key for developing a deep, savory flavor.
Pour in the crushed tomatoes and tomato puree.
Add the basil, parsley, oregano, and bay leaf, stirring well to combine all the .
Bring the sauce to a gentle simmer, then cover and cook for at least 10 minutes to allow the flavors to meld together.
Remove the bay leaf before serving and season with salt and pepper to your taste.