Grate the potatoes and the sweet onion using a box grater or food processor.
Place the grated potatoes and onion in a colander, wrap with a clean tea towel, and squeeze firmly to remove as much liquid as possible.
Transfer the drained potato and onion mixture to a large mixing bowl.
In a medium bowl, whisk together the eggs, minced garlic, flour, kosher salt, paprika, black pepper, and chopped dill until smooth.
Add the egg mixture to the potatoes and stir until well combined.
Heat the vegetable oil in a large skillet over medium-high heat until shimmering.
Drop 1/4-cup scoops of the potato mixture into the hot oil without overcrowding the pan, then gently press each mound to flatten into a pancake.
Cook the pancakes about 3–5 minutes per side, until deep golden brown, then flip and cook the other side.
Cook remaining batter, adding more oil to the skillet as needed between batches.
Serve the potato pancakes hot topped with sour cream and additional chopped dill if desired.