In a 6-quart dutch oven over medium heat, saute the diced onions, sliced celery, sliced carrots, and sliced mushrooms in 3-4 tbsp of vegetable broth. Cook the vegetables until the onions are translucent and the vegetables start to soften, about 10 minutes.
Add 4 cloves of minced garlic, 1 tbsp Italian seasonings, 2 tsp smoked paprika, ¼ tsp chili flakes, ½ tsp salt, and ½ tsp black pepper. Stir to combine and let it cook for 2-3 minutes.
Add 4 cups of vegetable broth, 3 cans of beans, and 2 cans of jackfruit. Bring the stew to a low simmer and then reduce the heat to medium. Let it cook for about 20 minutes or until the jackfruit is tender.
Use a wooden spoon to gently push each piece of jackfruit against the side of the pot to break it up into small chunks and shreds. If the jackfruit doesn't break apart easily, let the stew cook for another 5 minutes to continue to soften the jackfruit.
(Optional) To make the broth even thicker, use a stick blender to pulse the stew a few times (before you add the spinach) to naturally thicken the broth. If you don't have a stick blender, add one cup of the stew to a small blender and blend it until creamy and then pour it back into the pot.
Five to ten minutes before the stew is ready, stir in the frozen spinach and let it cook just until it has fully defrosted so it stays bright green.
Garnish each bowl with a sprinkle of chili flakes and green onions.