Preheat the oven to 400°F. Toss asparagus and jalapeño with a few tablespoons of canola oil and season with salt and pepper. Roast (at separate ends of a baking sheet) the asparagus until it is slightly charred and crisp tender (depending on size, 6-10 minutes) and the jalapeños until charred and soft (about 15 minutes).

Remove asparagus to a platter and put the jalapenos in a small bowl, cover and let sit for 15 minutes. After 15 minutes, remove the skin and seeds from the jalapeños and cut into small dice.

Increase the heat of the oven to 500°F. Lay 4 of the tortillas on a flat surface. Divide the cheese evenly over the top of each. On 2 tortillas, evenly divide the jalapeño and spring onion over the cheese. On the next 2 tortillas, layer 6-8 spears of asparagus (depending on size) and season with salt and pepper (these will be your base). Stack the tortillas with jalapeño and onion atop the asparagus layer to make two, 2-layer tortillas. Cover both with the remaining two tortillas. Brush the tops with oil and sprinkle each with 1 tablespoon of grated cheese and ancho chili powder. Transfer to an ungreased baking sheet and bake for 5-8 minutes or until golden brown and the cheese has melted. Put ricotta and lemon zest in a bowl and season with salt and pepper.