Bring sour cream to room temperature.
Peel, cut in half and slice one Spanish onion into 1/4" slices, slice white mushrooms into 1/4" slices and slice 2-3 dill pickles into thin spears and reserve.
Cut room temperature beef into 1" cubes. Mix 2 tablespoons of flour with 1/2 tablespoon ground black pepper and 1/2 tablespoon of kosher salt in a zip lock plastic bag. Add the cubed beef turning to coat each piece evenly.
Heat a medium sized sauce pan over high heat for a minute or so, then add 1 tablespoon oil and butter and heat until bubbly and hot.
Add beef and sear until each piece forms a crust, about 1-2 minutes per side. Don't crowd the beef or stir or move around; when done on one side, turn and sear the second side. When seared on all sides, remove beef to a platter and keep warm tented with aluminum foil.
With the setting still on high heat, add onions and cook for 2 - 3 minutes. The onions should be crisp tender and not soggy. If the pan seems dry, add a little oil, and stir once or twice to evenly cook onions. Remove onions to the platter with the seared beef, but keep separately to one side.
With the setting still on high heat, add wine and consommé scraping up the bits from the bottom of the pan and simmer until the liquid is reduced by half.