Turn your oven on to 200°C / 400° F to preheat while you get the chopping done.
Chop the onion, crush the garlic, mince the jalapeño, dice the zucchini and red pepper, and set everything into little bowls or on plates. Now you're ready to go!
Heat the oil in a large skillet over medium-high heat.
Add the onions and sauté for about 6-8 minutes, stirring frequently, until the onions are soft and beginning to take on a bit of colour.
Add the garlic and jalapeños and sauté for about 2 minutes more.
Now add the zucchini and red pepper and sauté for 8-10 minutes. The vegetables should be softened but not mushy, and just starting to brown.
At this point add the corn, and tomato and sauté for 2-3 minutes, until the mixture is well heated. Add the black beans, cumin, smoked paprika, chilli, and salt. Stir to combine well.
Taste, and adjust seasonings if necessary. Stir in the cilantro, and remove from the heat.
Line a baking sheet with parchment paper or tinfoil. Place one tortilla on the baking sheet, and spoon about 1/4 - 1/5 of the filling onto it, spreading it right to the edges. Sprinkle with cheese if using, top with another tortilla. Press down in the center of the next tortilla a bit to prevent a dome shape from forming, and then spoon some more filling on.
Repeat layers of filling, cheese, and tortilla until you've run out of filling.
Finish with a tortilla on top, and sprinkle it with cheese and a bit of green onion if desired.
Place into the oven and bake for about 30 minutes, until the cheese on top is brown and bubbly.
Remove from the oven and let stand for about 10 minutes before slicing into wedges to serve.