Step 1

Divide 1 lb. fresh chorizo or other spicy sausage, casings removed, into 4 equal portions, then flatten into thin patties (roughly the size and shape of your bread slices). Separate patties with parchment or wax paper if stacking.

Step 2

Heat 2 Tbsp. vegetable oil in a large skillet over medium-high. Working in 2 batches if needed, cook patties, pressing down with the back of a sturdy metal spatula to ensure good contact with the pan, until lightly browned, about 2 minutes per side. Transfer to a plate, leaving fat behind.

Step 3

Add 1 medium red onion, thinly sliced, to same skillet; season with kosher salt. Cook, stirring occasionally, until slightly softened, about 2 minutes. Add 2 poblano chiles, ribs and seeds removed, thinly sliced, and 1 cup coarsely chopped sliced pickled jalapeños and cook, stirring occasionally, until poblanos are softened but still retain some bite, 6–8 minutes. Transfer to another plate. Wipe out skillet and reduce heat to medium.

Step 4

Top 4 slices sourdough bread with 8 oz. Oaxaca cheese or fresh mozzarella, torn, dividing evenly, then top with patties, onion mixture, and remaining 8 oz. Oaxaca cheese or fresh mozzarella, torn. Close up sandwiches with remaining 4 slices sourdough bread and spread top of each with a little mayonnaise.

Step 5

Working in 2 batches if needed, place sandwiches in skillet, mayonnaise side down, cover with a sheet of foil, and weight with another heavy pan (the foil keeps the pan clean while it presses the sandwiches). Cook until exterior of bottom slice is golden brown, about 3 minutes. Remove top pan and foil and spread top of each sandwich with a little mayonnaise. Turn sandwiches over, re-cover with foil, and weight with pan. Cook until other side is golden brown and cheese is melted, about 3 minutes.