Special equipment: meat grinder
Preheat the oven to 375 degrees F.
For the filling: Place the meat, carrots, celery and chopped onions in a large Dutch oven. Add the bottle of red wine and cook in the oven, covered, until the meat is fork tender, about 1 1/2 hours. Remove the meat from the oven and let it cool. In a large skillet over medium heat, saute the sliced onions in canola oil until they are translucent, about 10 minutes. Remove the onions from the heat and let them cool.
Chop the cooled meat into large pieces that will fit into the spout of a meat grinder. Using the meat grinder, alternate grinding the meat and the caramelized onions until it has all been ground together. Taste the mixture, and adjust the seasoning with salt and pepper.
For the dough: While the meat is cooking, place the flour and eggs in a food processor and process until the mixture forms into dough. Remove the dough from the food processor and cover it with a dry dishtowel. Let it rest on the counter for 30 minutes.
While the dough is resting, bring a large pot of water to a boil. Once boiling, lower the heat so the water is simmering.
Cut the dough into quarters. Leaving the other sections covered with the dishtowel, take one section and roll it out on a well-floured surface until it's about 1/4-inch thick. Cut the rolled-out dough into 2-inch squares. Place a teaspoon of meat filling onto the center of each piece of dough. Wet the sides of the dough with water and fold the dough corner to corner, crimping the dough together with your fingers to form a triangle. Join the two ends of the triangle together to form a little ring, similar to tortellini. Repeat the filling and shaping process with the rest of the dough.
Place small batches of kreplach carefully into the pot of simmering water. When they rise to the top of the water, cook them for another 5 minutes. When the kreplach are finished cooking, remove them from the pot with a strainer and place them in a bowl with a little bit of oil. This will prevent them from sticking together.