Heat olive oil in a large pot or deep skillet over medium heat.
Add the chopped onion and cook until translucent, about 3-4 minutes.
Add the minced garlic and cook for another 1 minute until fragrant.
Add the raw shrimp to the pot and cook until they turn pink and are just cooked through, about 2-3 minutes. Remove shrimp from the pot and set aside.
Add the dry spaghetti pasta to the pot.
Pour in the chicken broth and the canned diced tomatoes with their juices.
Add crushed red pepper flakes, dried oregano, dried basil, salt, and black pepper.
Bring the mixture to a boil, then reduce heat to medium-low and simmer uncovered.
Cook, stirring occasionally, until the pasta is tender and most of the liquid is absorbed, about 10-12 minutes.
Return the cooked shrimp to the pot and stir to combine and warm through, about 2 minutes.
Remove from heat and stir in fresh parsley and lemon juice.
Adjust seasoning with additional salt and pepper if needed.
Serve hot.