This melt-in-your-mouth jammy tomato-onion spread is absolutely worthy of a 1-hour simmer. It's a delicious appetizer all on its own served with crackers or crostini, or as an addition to a cheeseboard. Or, add the savory spread to sandwiches or mix into eggs.
Remove tomato skins: make a cross-slit in the top of the tomatoes. Bring a saucepan of water to a boil and add the tomatoes for 1 minute. Remove tomatoes and put them in an ice bath. Remove and peel off the skins. Cut the tomatoes into quarters, remove their seeds, and then dice the flesh.
Heat a ceramic pot or dutch oven over medium heat (stainless steel and tomatoes can react to have a metallic taste so it's best to avoid those). Add the olive oil. Once hot, add the diced onion and cook for 5-7, stirring occasionally, until tender. Add the tomatoes, red bell pepper, and garlic. Add a pinch of salt. Simmer with a lid for 30 minutes.
After the 30 minutes have passed, remove the lid and continue simmering for another 30 minutes, stirring occassionally. Other the hour, the consistency will become more jam-like.
Taste for salt levels and adjust as needed. Remove from heat and let cool; serve room temperature or warm.
Notes
To store, place in an airtight container in the fridge. The olive oil will solidify, so when you want to eat it again, just bring it back to room temperature and stir. This recipe makes approximately 3/4 cup.