Heat olive oil in a heavy skillet over medium heat. Add red chili flakes and heat for 30 seconds until fragrant. Add diced onion and cook 3-4 minutes until softened. Stir in minced garlic and cook 30-45 seconds until aromatic but not browned.
0.25 cup olive oil, 1.5 tsp red chili flakes, 1 small onion, 6 cloves garlic
Pour in white wine and simmer for 2 minutes to reduce by half. Add crushed tomatoes and salt, then stir to combine. Bring to a gentle simmer, reduce heat to medium-low and cook uncovered for 15 minutes, stirring occasionally, until the sauce thickens and reduces slightly.
0.5 cup white wine, 28 oz crushed tomatoes, 1 tsp salt
Pat shrimp dry with paper towels and season with salt. Push sauce to sides of pan and add shrimp in a single layer with about 1 inch space between pieces. Cook 2-3 minutes per side until shrimp turn opaque with a slight curl. Cook in batches if needed to avoid crowding.
1.5 lbs shrimp, 1 tsp salt
Gently stir cooked shrimp into the sauce to coat. Remove from heat and stir in lemon juice. Taste and adjust seasoning with additional salt or chili flakes if needed.
1.5 lbs shrimp, 2 tbsp lemon juice, 1.5 tsp red chili flakes, 1 tsp salt
Garnish with chopped fresh parsley and serve immediately, spooning extra sauce over pasta, rice, or crusty bread if desired.
0.25 cup fresh parsley
