Preparation

• Place the chicken breasts into a large saucepan. Pour in the water, and season with chili powder, ½ teaspoon salt, cumin, ¼ teaspoon black pepper, garlic powder, onion powder, and cayenne pepper. Bring to a simmer over high heat, then reduce heat to medium-low, and simmer 15 minutes.
• After 15 minutes, stir in 4 ounces of green chiles, onion, and garlic; continue simmering until the liquid has reduced to 1 cup. Reserve remaining 3 ounces of chopped green chilies.
• Remove the chicken, shred with two forks, and return to the onion mixture.
• Meanwhile, melt the butter in a small saucepan over medium heat. Stir in the flour, and cook for 1 minute. Whisk in the water and bouillon cube until the water has thickened and the bouillon cube has dissolved, about 4 minutes. Whisk in reserved 3 ounces of green chilies and the sour cream; season to taste with salt and pepper. Keep warm.
• Heat oil in a deep-fryer or large saucepan to 375 degrees F (190 degrees C).
• Place a tortilla onto your work surface, then spoon about ⅓ cup of the chicken filling halfway between the bottom edge and the center of the tortilla. Flatten the filling into rectangle shape with the back of a spoon. Sprinkle about 1 ounce of the Monterey Jack cheese over the filling.
• Fold the bottom of the tortilla snugly over the filling, then fold in the left and right edges. Roll the chimichanga up to the top edge, forming a tight cylinder; secure the ends with wooden toothpicks. Repeat with the remaining ingredients.
• Cook the chimichangas, 2 at a time, in the hot oil until they are crisp and golden brown on both sides, about 1 minute per side.
• Drain on a paper towel-lined plate, and remove toothpicks.
• Top with sour cream sauce to serve.