• Before starting, preheat the oven to 450°F.
• Wash and dry all produce.
• Bring a large pot of salted water to a boil over high.
• Meanwhile, thinly slice mushrooms.
• Roughly chop spinach.
• Strip tarragon leaves from stems, then finely chop.
• Zest, then juice lemon.

• Pat steak dry with paper towels. Season with pepper, half the garlic salt and half the Lemon-Pepper Seasoning.
• Heat a large non-stick pan over medium-high.
• When hot, add 1 tbsp (2 tbsp) oil, then steak. Cook for 1-2 min per side, until browned. Don't crowd the pan; cook in batches, if necessary. (TIP: If steak has a thick fat cap, sear fat-side down for 1-2 min.) (NOTE: Steak will finish cooking in step 3.) Remove from heat and transfer steak to an unlined baking sheet.
• Carefully wipe the pan clean.

• Roast steak in the middle of the oven for 5-8 min, or until cooked to desired doneness.** 
• When steak is done, transfer to a clean cutting board. Loosely cover with foil and set aside to rest for 2-3 min.

• Reheat the same pan (from step 2) over medium-high.
• When hot, add 1/2 tbsp (1 tbsp) oil, then mushrooms and 1/4 cup (1/2 cup) water. Cook for 5-6 min, stirring occasionally, until softened. Season with pepper and remaining garlic salt.
• Transfer mushrooms to a plate.
• To the pan, add cream, half the Parmesan, remaining Lemon-Pepper Seasoning, 1/2 cup (1 cup) milk and 1/4 tsp (1/2 tsp) salt. Cook for 1-2 min, stirring often, until cheese melts and sauce thickens. 
• Remove from heat, then stir in 1/2 tsp (1 tsp) lemon zest and 1 tbsp (2 tbsp) lemon juice.

• Meanwhile, to the boiling water, add linguine. Cook for 2-4 min, stirring occasionally, until tender but still firm to the bite.
• Reserve 1/4 cup (1/2 cup) pasta water. 
• Strain linguine, then return to the pot, off heat.

• Thinly slice steak.
• To the pot with linguine, add creamy sauce, any steak resting juices, spinach and half the tarragon. (TIP: For a lighter sauce consistency, add reserved pasta water, 1-2 tbsp at a time.) Toss to combine, until spinach wilts.
• Divide linguine between plates. Top with steak.
• Spoon sautéed mushrooms over steak.
• Sprinkle with remaining tarragon and remaining Parmesan.

If you've opted for double steak, cook in the same way the recipe instructs you to cook the regular portion of steak. Work in batches, if necessary.