Melt the butter in a medium saucepan over medium-low heat. Add the flour and cook, stirring continuously, until browned and the raw smell dissipates, about 2 minutes. Add the curry powder, garam masala, ketchup, Worcestershire sauce, ½ teaspoon kosher salt, and pepper. Cook, stirring continuously, for 1 minute.
Slowly whisk in 1 cup water, adding a little at a time to ensure the mixture is smooth and doesn't get lumpy. Bring to a boil and simmer, stirring frequently, until the sauce has thickened. Transfer ½ cup to a large bowl and let cool to room temperature. Reserve the remaining sauce in a separate bowl for serving.
After the sauce in the bowl has cooled, add the pork, chicken, peas, onion, ginger, and the remaining 1 teaspoon kosher salt. Use your hands to work all the ingredients together until well-mixed. It’s best to use your hands because you can get everything incorporated into the meat without making the pieces of meat too small.
If you have time, cover and refrigerate the filling until nice and cold, up to 2 days. The filling will be easier to spoon into your wrappers when it’s chilled.
Take out five or six wrappers and cover the rest so they don't dry out. Lay out the wrappers on a work surface. Wet ½ inch of the rim of each wrapper with water (just use your finger).
Scoop 1 tablespoon of filling into the center of each wrapper, shaping it elongated like a football to make it easier to fold. Fold the wrapper in half like a taco and pinch the edges at the top center. Continue folding the dumpling using your preferred folding method (simply press the edges together or pleat to create another shape).
At this point, the dumplings can either be cooked immediately, covered and refrigerated for up to a couple hours, or frozen.
When you’re ready to cook your dumplings, use a medium or large nonstick skillet with a lid (or cook two batches at the same time using two pans). Heat the skillet over medium-high heat and add about 1 tablespoon neutral oil (like vegetable oil).
Place the dumplings 1 at a time, sealed edges up, in a winding circle pattern. The dumplings can touch. Medium skillets will generally fit 12 to 14 dumplings, large skillets will fit 16 to 18 dumplings. Fry the dumplings for 1 to 2 minutes until they are golden or light brown on the bottom.
Holding the lid close to the skillet to lessen splatter, use a measuring cup to add water to a depth of roughly ¼ inch (about ⅓ cup water). The water will immediately sputter and boil vigorously. Cover with a lid or aluminum foil, lower the heat to medium, and let the water bubble away for 8 to 10 minutes, until it is mostly gone. When you hear sizzling noises, remove the lid as most of the water is now gone. Let the dumplings fry for another 1 or 2 minutes, or until the bottoms are brown and crisp. Turn off the heat and use a spatula to transfer dumplings to a serving plate. Display them with their bottoms facing up so they remain crisp.
Reheat the remaining curry sauce in a small saucepan (or in the microwave, if necessary), thinning it out with a few spoonfuls of water as needed to obtain your desired consistency. Serve the dumplings with the reserved dipping sauce.