Soak the tomatoes in 3/4 c warm water & 3/4 c warm vinegar for 2 to 3 hours. Drain & set on a kitchen towel.
Pat dry. Stir together the basil, red pepper flakes, garlic & salt. In a 12 ounce jar, alternate layers of the tomatoes with the basil mixture.
Pour in the olive oil, making sure that it covers the top layer. Eliminate any air bubbles. Screw on the lid & seal well. Marinate for 1 day before using.
NOTE: Do not use overly salty tomatoes. Ensure that the tomatoes are dried by the sun & not by an oven & that they are not already preserved in oil. Serve with bread.