Step 1Heat a heavy pot over medium heat until hot. Add enough olive oil to coat the bottom of the pan by 1/8-inch, ½ to 1 cup. Add the garlic and sage and cook until the garlic is aromatic, but before it browns, and the sage begins to crisp, about 1 minute. Stir in the tomatoes, along with a tablespoon of salt and the basil.
Step 2Cover and cook over medium heat until the tomatoes give off their liquid and begin to break down, checking and stirring the mixture occasionally, about 10 minutes.
Step 3Remove the lid and continue to break down the tomatoes using a potato masher or sturdy whisk. Taste and check the sauce for salt, and add a few grinds of black pepper or a healthy pinch of chile flakes.
Step 4Remove the sauce from heat and run it through a food mill, then place back in the pot and bring to a simmer. Add half of the bread, torn into big pieces, along with a good drizzle of olive oil. (Don’t worry about the hard crust; it will soften in the sauce.)
Step 5Bring the sauce back to a simmer for a few minutes, then remove from heat, cover and set aside for at least 15 minutes to give the bread time to soften and expand. Stir to check the consistency; for thicker sauce, add more bread, one slice at a time, and giving it time to break down before adding any more.