Bring a large pot of salted water to a boil and cook pasta according to package directions. Season steak all over with Salt & Pepper Tableside Seasoning. Heat 1 Tbsp. oil in a large skillet over medium-high heat. Sear steak 4 min. per side (for medium doneness) then transfer to a plate to rest. Add remaining 1 Tbsp. oil and mushrooms to skillet. Saute mushrooms for 5 to 8 min. or until softened and starting to brown. Add bell pepper and onion to skillet and cook for 1 min. Meanwhile, in a separate pan, melt butter over medium heat. Whisk in heavy cream, sour cream, and Onion & Garlic Tableside Sprinkle. Bring just barely to a simmer, then reduce heat to low and keep warm. Slice rested steak into strips and add to skillet. Pour warm sauce into a large bowl. Add Parmesan cheese and pasta. Toss to coat. Add Salt & Pepper Tableside Seasoning to taste. Serve as a bed of sauced pasta with steak & mushroom medley on top. Garnish with more Parmesan cheese to taste.