Heat olive oil in a large pot over medium heat.

Add chopped onion and sauté until translucent, about 5 minutes.

Stir in minced garlic and cook for another minute until fragrant.

Add crushed tomatoes, tomato paste, sugar, oregano, basil, salt, and pepper.

Bring to a simmer, then reduce heat to low and let it cook for 30 minutes, stirring occasionally.

Taste and adjust seasoning if necessary.