Preheat your smoker to 200°F.
Cook the onions and garlic in 1 tbsp oil over medium-low heat until soft and translucent. Let cool for ten minutes.
Mix together the venison, egg, breadcrumbs, 1 tbsp finely chopped dill, 1 tbsp whole grain mustard, 1 tsp salt, ½ tsp ground pepper, and the cooled onion and garlic in a bowl.
Roll meat mixture into evenly sized meatballs.
Add 1 tbsp oil to the frying pan and sear meatballs on all sides over medium high heat.
Leaving meatballs in the frying pan, move them to the smoker and let smoke for roughly 30 minutes.
In a separate large frying pan, melt 2 tbsp butter over medium-high heat.
Add the mushrooms and a pinch of salt to the pan and toss to coat in the melted butter.
Cook until the pan juices have evaporated and the mushrooms are golden brown.
Lower heat to medium, stir in ½ tsp paprika and 1 tbsp all-purpose flour.
Pour in 2 cups of beef stock and bring to a simmer. Scrape loose any bits that are stuck to the pan as it starts to simmer.
Remove the mushrooms with a slotted spoon and set aside.
Bring the liquid to a boil for 5 minutes, then mix in 1 tbsp whole grain mustard, 2 tsp dijon mustard, 1 tbsp tomato puree, and 1 cup of sour cream.
Stir together and let simmer until the sauce has thickened and coats the back of a spoon. Roughly 20 minutes.
While the sauce is simmering, cook half a pound of tagliatelle pasta according to the package (8 oz uncooked). Drain the noodles and set aside until the sauce finishes.
Put the meatballs and the mushrooms into the simmering sauce.
Make sure the meatballs are cooked all the way through at a temperature of at least 160°F. Season the mixture to taste. Note - you can add a pinch or two of sugar if you prefer a sweeter sauce than a sour one.
Plate the noodles in a pasta dish, and cover with the stroganoff.
Garnish with chopped dill and serve hot.