California Chicken Sandwich Recipe

Prepare guacamole

Halve the avocado and scoop 1/2 avocado into a small bowl. Mash with a fork until slightly chunky. Add lime juice, minced red onion, chopped cilantro, salt, pepper, and minced jalapeño if using. Stir to combine, taste and adjust seasoning. Set aside at room temperature while you cook the chicken.

Pound and season chicken

If the chicken breast is thick, butterfly or pound to an even thickness about 1/2 inch so it cooks evenly. Pat dry with paper towels. Season both sides with 1 tsp salt, 1 tsp black pepper, and 1/2 tsp garlic powder.

Cook chicken

Heat 1 tablespoon olive oil in a medium skillet over medium-high heat until shimmering. Add the seasoned chicken breast and cook 4–6 minutes per side, depending on thickness, until golden brown and internal temperature reaches 165°F (74°C). Reduce heat if the exterior browns too quickly. In the last minute of cooking, top the cooked side with the pepper jack slice, cover the pan briefly to melt the cheese (about 30–60 seconds). Remove chicken from pan and let rest 3–5 minutes, then slice if desired.

Toast roll

While the chicken rests, split the ciabatta roll and lightly butter or brush with olive oil. Toast cut sides in the same skillet over medium heat for 1–2 minutes until golden and crisp. Remove from heat.

Assemble sandwich

Spread mayonnaise (if using) on the bottom half of the toasted roll. Spread a generous layer (about the prepared amount) of guacamole on the top or bottom half per preference. Place a handful (about 3/4 cup) of baby spinach on the bottom half, then add 2 slices of tomato. Place the rested, cheese-topped chicken breast on the tomatoes, then close the sandwich with the guacamole-topped half. Press gently and serve immediately.

Cut sandwich in half if desired and serve hot. Optionally serve with kettle chips, fries, or a small salad.