Fry the mushrooms in the pot until released all the water and until browned, then add a bit of soy sauce.
Add the onions, garlic and tomato paste and fry until fragrant.
Then the crushed tomatoes as well as the vegetable stock and simmer for about 10 min.
Afterwards add the beans and the corn and simmer for a bit more and season.
If the chilli is still a bit to watery then add corn starch to a bit of water and add this slurry to the chilli, bring the chilli to a boil and check the consistency again.