Combine all the ingredients for the filling in a medium bowl. Mix well with a spoon. Cover with a wrap and refrigerate until needed.
To make the chimichurri, in a small bowl, combine the chopped shallot and vinegar. Let the onion marinate for 20 to 30 minutes. Strain, reserving the shallots and the vinegar separately. In a food processor, combine the shallots, herbs, peppers, oil, and 2 tablespoons of reserved vinegar. Pulse briefly until you get a chunky mixture. Transfer the sauce into a bowl and season to taste with salt and the rest of the vinegar. The sauce should be used within 2 hours.
Mix flour and salt in a large bowl. Make a well in the center of the flour mixture, add oil and start slowly pouring the hot water. The mixture will be very hot so start mixing it with a spatula or a large wooden spoon. When the dough starts coming together and becomes warm enough to handle, transfer it to a lightly floured surface. Knead the dough for a few minutes, until almost smooth. Wrap it in plastic and let rest for 20 minutes.
You can refrigerate the dough up to 6 hours, before making the dumplings. Make sure the dough is room temperature before starting rolling.
Lightly flour the work surface. Divide the dough into 2 equal parts and roll into a large 1/8-inch thick circle. Using a 4-inch round cookie cutter, a glass, or a cup, cut circles of dough. Repeat with the other half of the dough and scraps. Keep the dumpling wrappers covered with a kitchen towel to prevent them from drying out
To assemble the dumplings, place a tablespoon of the meat filling right in the center of your wrapper. Fold the wrapper in half and pinch to seal it in the middle. Then close two open sides to form a rectangular with 4 corners. Pinch the opposite corners together to create a rose-shaped dumpling.
Heat the oil in a large non-stick or cast iron skillet over medium heat. Working in batches, add dumplings in a single layer and cook until bottoms begin to brown, about 1 minute seconds. Add 1/3 cup water, cover the skillet with a lid and cook for about 3 minutes. Then remove the lid and cook until the liquid has evaporated completely and the bottoms are crisp and golden brown, about 2 more minutes. Repeat with remaining dumplings. Serve with cilantro chimichurri and sour cream.
If you want to save dumplings for later, place the dumplings on a lightly floured tray or cutting board and freeze. Once the dumplings are solid, place them in ziplocks and store until needed.