Heat 2 tbsp of oil in a skillet over medium heat. Add 1 medium finely diced onion and sauté until it turns translucent, about 2-3 minutes. Add 4 cloves of finely diced garlic and sauté for another minute, making sure not to burn the garlic. Next, add 1 finely diced green chili and 2 red chilies for a little heat and color.
To the sautéed vegetables, add 3 tbsp all-purpose flour and cook for about a minute to eliminate the raw flour taste. Gradually pour in ½ cup of chicken stock, stirring constantly until the mixture thickens. This creates a creamy roux that will hold your chicken croquettes together.
Take 500g of boiled and shredded chicken (you can use any part, but breasts work well) and stir it into the roux. Season with ¼ tsp of salt, ¼ tsp freshly cracked black pepper, and a dash of freshly grated nutmeg. Mix everything well and then remove the skillet from the heat to allow the mixture to cool slightly.
In a separate bowl, rice or mash 400g of boiled potatoes. Add 2 tbsp of room temperature salted butter and stir until the butter melts into the potatoes. Mix in 2 egg yolks, 1 tbsp lemon juice, ½ cup grated mozzarella, and ½ cup grated cheddar cheese for a creamy, cheesy filling. Sprinkle in 2 tbsp chopped cilantro for a fresh burst of flavor.
Once the chicken mixture has cooled, fold it into the potato mixture. Mix until everything is well incorporated. With oiled hands, form the mixture into small balls or logs, depending on your preferred shape. Place the croquettes on a baking dish, cover them with plastic wrap, and refrigerate for 1 hour to firm them up.
Set up your workstation with 1 cup of all-purpose flour, beaten egg whites, and 1 cup of breadcrumbs. Take each croquette and first roll it in flour, then dip it in the egg whites, and finally coat it in breadcrumbs.
Heat oil in a deep fryer or deep pan over medium heat. Test the oil by inserting a bamboo skewer—if bubbles rise around the skewer, the oil is ready. Fry the croquettes in batches, about 3-4 at a time, ensuring not to overcrowd the pan. Fry until golden brown and crispy, about 3-4 minutes on each side.
Drain the croquettes on a paper towel or colander. For a festive touch, serve them with a dollop of ketchup on top, a blistered tomato, and a bamboo skewer to hold it all together. Garnish with fresh cilantro.