Preheat oven to 250 degrees.
Heat the canola oil in a Dutch oven over high heat for about one minute.
Add onions and mushrooms and brown for about one minute.
Remove from the pan.
Return pan to high heat and brown the meat, about one minute per side.
Return the onions and mushrooms to pan.
Add the water, Dijon mustard, and beef bouillon.
Bring mixture to a boil while stirring.
Place in preheated oven and cook for 2-3 hours or until beef is very tender.
Right before serving, stir in the sour cream.
Season with salt and pepper, as desired.
Serve immediately, garnished with chopped dill (or stir in a little of the dill paste).
I serve over mashed potatoes.