Grind the croutons in a food processor until breadcrumb like. Deseed and chop the jalapeños, and set them aside.
In a large bowl, roughly “mush” the black beans using a large spoon. Add the tomato paste, mushrooms, and chilies.
Mix in the crouton crumbs. Drizzle with olive oil and a big squirt of Sriacha. Form into 8 patties (about 1/2 inch thick) and place onto greased aluminium foil to keep the patties together.
Top with sliced cheese and chopped jalapeños. They will take about 12 minutes at 300 degrees Fahrenheit on the grill.