Fill a medium pot with water and add a pinch of salt. Turn the heat to high and wait for it to boil.
Add the spaghetti to the boiling water. Cook for 8–10 minutes until soft. Drain and set aside.
Put a pan on medium heat and add the olive oil. Pour in the diced tomatoes. Cook for 3–4 minutes, stirring occasionally.
Add the peas to the pan. Stir and cook for 2–3 minutes until heated through.
Add the drained spaghetti to the pan. Sprinkle in salt, black pepper, garlic powder, and oregano if using. Stir everything so the pasta is coated with the sauce.
Turn off the heat and serve warm.
