Prepare the meatballs first. Grate the onion into a large mixing bowl, then add the ground turkey meat, egg, bread crumbs, salt, pepper, coriander, parsley and dill. Using a spatula or your hands, gently combine the ingredients together, just until uniform. Do not overmix the meatball mixture. Using a 1 tablespoon (15 ml) scoop, measure out the meat mixture for each meatball and gently roll to shape into a ball. Watch my video recipe to see how it's done.
Preheat a large saute pan over medium-high heat and add a few tablespoons of cooking oil. Once the oil is hot, add the meatballs into pan. Fry the meatballs for 7 to 8 minutes, turning every few minutes, until they're well browned all over. The meatballs do not need to be thoroughly cooked; they will finish cooking in the sauce. Remove the browned meatballs onto a clean tray and set aside.
Reduce the pan heat to medium and add in the butter. Once melted, add the sliced mushrooms and shallot. Saute the mixture for about 5 minutes, until the mushrooms are lightly browned. Add in the garlic, salt, pepper and paprika next and cook for another minute. Next, add in the wine (or lemon juice) and cook for a few minutes, until the wine is reduced. Add in the flour, stir until well combined and cook for 1 minute.
Begin adding the milk gradually, whisking it into the mushroom mixture. Stir in the chicken broth and return the meatballs to the pan. Bring the sauce up to a simmer over medium heat and simmer for 8 to 10 minutes, until the sauce is thickened. The sauce will continue to thicken once it's removed from heat. Sprinkle the dish with more fresh parsley and dill, then serve over prepared mashed potatoes, pasta or egg noodles.
For Mashed Potatoes:
First wash and peel the potatoes. Keep the potatoes in a bowl of cold water to prevent browning. Using a sharp knife, cut the potatoes into medium sized chunks and place into a large pot. Add the chicken or vegetable broth, salt and enough water to cover the potatoes by a few inches.
Bring the potatoes up to a boil over high heat, then reduce the heat to medium-high and cook for another 15 to 20 minutes, until the potatoes are very soft but not falling apart. Cooking time depends on size of potato pieces. Drain the potatoes after cooking.
Transfer the potatoes into a large mixing bowl, or do the next steps in the pot. Add the softened butter and cover it with the potatoes to melt it faster. Once the butter is melted, add a few tablespoons of cream, then use a potato masher or a hand mixer fitted with beaters and mash the potatoes.
Continue mashing the potatoes and adding more cream as needed, until the potatoes are creamy and smooth. Season with salt to taste.