Chicken and Mushroom Chimichangas

Preheat the oven to 400 degrees F (200 degrees C). Line a heavy baking sheet with parchment paper or a silicone baking mat.

Heat 1 1/2 teaspoons vegetable oil in a heavy skillet over medium-high heat. Add onion, poblano peppers, and mushrooms; season with salt and black pepper. Cook until soft, about 5 minutes; continue cooking until vegetables begin to brown, 5 to 10 minutes more.

Move vegetables to edges of the skillet, leaving a space in the center. Drizzle 1 1/2 teaspoons vegetable oil into center. Add chicken pieces to the center; season with cumin, ground chipotle, Mexican oregano, salt, and black pepper. Cook and stir until chicken pieces are browned, about 5 minutes.

Stir chicken and vegetable mixture together. Off heat, drizzle water over chicken mixture; scrape browned bits of food off the bottom of the skillet with a wooden spoon. Transfer mixture to a bowl; set aside to cool. Wipe the skillet clean.

Stir pepper Jack cheese into chicken mixture to combine; season with cayenne pepper, salt, and black pepper.

Heat the same skillet over medium heat until hot. Add 1 tortilla to the skillet; heat until warmed and flexible, about 30 seconds per side.

Place tortilla onto a work surface; spoon 1/4 filling in a line across middle of the tortilla. Fold bottom of tortilla just over filling; brush top and exposed inside parts of tortilla with egg white. Fold right and left sides towards the center like an envelope, enclosing filling. Roll tortilla to enclose filling in a rectangular packet. Repeat with remaining tortillas and filling.

Heat remaining 2 tablespoons vegetable oil in the skillet over medium heat. Add chimichangas; cook on both sides until golden brown, 2 to 3 minutes per side. Transfer to the prepared baking sheet.

Bake in the preheated oven until tortilla is puffed up, golden brown, and outside is crisp, 12 to 15 minutes. Spoon 1 tablespoon guacamole, 1 tablespoon sour cream, 1 tablespoon salsa, and 1 tablespoon cilantro onto each chimichanga to serve.