Preheat oven to 200 degrees C. Slice the peppers in half and remove the core and seeds. Slice in to ribbons, drizzle with a little oil and place on a roasting tray. Roast for 25 minutes or until soft. Remove from the oven and set aside.
Meanwhile, pour boiling water over the dried porcini mushrooms in a bowl and set aside for 10 minutes.
In a small pan, heat the oil and add the garlic. Cook for thirty seconds before adding the bay leaves, paprika and oregano. Cook for another thirty seconds.
Add the chopped mushrooms and stir to coat. Cook the mushrooms for 2 minutes until they are beginning to soften.
Add the chopped tomatoes and strain the mushroom liquid from the porcini mushrooms in to the pot. Add the soy sauce.
Chop the now hydrated porcini mushrooms and add them to the pot too.
Cook the mixture for around 20 minutes or until the liquid has cooked down and the mixture resembles a beef ragu.
Take it off the heat and stir in the chopped spinach leaves.
To assemble the sloppy joes, lightly toast the burger buns on a griddle. Lay a few pepper ribbons on the bun base and top with a good few spoonfuls of the ragu. Top with the bun top and serve.