Heat olive oil over medium heat. Add shrimp in a single layer and season with a pinch of salt. Cook until shrimp is bright pink (no gray), turning every minute or so. Transfer to a plate.
Add onion to the pan and cook until onion starts to soften; about 2-3 minutes. Add garlic and continue to cook for 2 more minutes. Stir often so the garlic doesn't burn.
Stir in apple juice, lemon juice, ½ teaspoon salt, oregano and red pepper flakes. Bring to a simmer and add cherry tomatoes. Simmer about 3-5 minutes, stirring often.
Toss shrimp with the sauce, then the linguine. Sprinkle fresh grated Parmesan on top of the pasta and toss lightly. Garnish with fresh chopped parsley and serve immediately.
Notes
For a richer, thicker sauce, save a cup of the cooking water from the pasta. Add it to the pan of sauce and simmer until reduced by half.