Pour tomatoes and juice into a large bowl. Open tomatoes with hands and remove and discard seeds and fibrous cores; let tomatoes drain in china cap until excess liquid is removed, about 5 minutes.
Reserve 2½ cups tomato juice and discard remainder.
Heat 2 tablespoons oil in large saute pan over medium heat until shimmering. Add onion and cook until softened and lightly browned, 5 to 7 minutes. Stir in garlic and oregano and cook until fragrant, about 30 seconds
Stir in strained tomatoes and increase heat to medium-high. Cook, stirring often, until liquid has evaporated, tomatoes begin to stick to bottom of pan, and brown fond forms around pan edges, 10 to 12 minutes.
Stir in a small amount of the reserved tomato juice and cook until thick and syrupy, about 1 minute. Continue to add reserved tomato juice and reduce, scraping up any browned bits, until all juice has been added. Remove from heat when sauce has thickened to desired consistency.
Stir in basil and remaining 1 tablespoon oil, and season with salt, pepper, and sugar to taste.
Notes
Marinara sauce originated in southern Italy in the mid-1600s. It is named for the sailors (marinai – italian for sailors) who manned the ships that were the backbone of the sea trade that flourished long before the 19th century.There are two explanations as to how the sauce came to be named for the sailors. One is that its ingredients – oil, tomato sauce, garlic and dried herbs – traveled well and didn’t spoil easily, as meat or fish did. The ingredients could be assembled quickly and easily, in about the same time it took pasta to cook, and the two together made a tasty, filling and inexpensive meal for men at sea.A more romantic story holds that when sailors’ wives spotted homeward bound ships on the horizon, they hurried to make this sauce so their hungry men could have a hot meal the minute they walked in the door.Variations:
Add red pepper flakes and you have spicy arrabbiata sauce.
Add anchovies in addition to the pepper flakes and you have puttanesca.