Russian-Style Beef Tenderloin Stroganoff

Sauté the onion in butter or olive oil until lightly browned.

Add the beef tenderloin, cut into cubes, already seasoned with salt, olive oil, and black pepper.

Cook the meat until browned on all sides.

Add the Russian mustard and smoked paprika. Mix well.

Incorporate the heavy cream and mix gently. Cook for a few minutes until heated through.