Preheat the oven to 180°C (160°C fan).
Add 1 ½ tins of butter beans to a baking dish and drizzle with olive oil and balsamic vinegar. Swirl them around to evenly coat the beans.
Pour in the tin of chopped tomatoes, then season with oregano and add a few torn basil leaves - keeping some aside for later. Season with salt and pepper, then stir to evenly mix everything.
To make the cheesy bean sauce, combine the remaining butter beans, plant milk, cashews, nutritional yeast, garlic, mustard and lemon juice in a high-speed blender. Once smooth, season to taste with salt and pepper.
Pour the cheesy bean sauce over the butter beans in the oven dish. Sprinkle a few torn basil leaves over the top and transfer to the oven. Bake for 25-30 minutes or until golden on top.
Garnish with the remaining fresh basil leaves and serve this delightfully cheesy bean bake with a slice of garlic bread or as a bean-loaded side dish.