In a medium skillet, place the tomatoes and olive oil over medium high heat. Add the saffron and season with salt and pepper. Give the mixture a stir to combine.
Once the oil starts to get hot, and the tomatoes start to blister, reduce the heat to medium low and let simmer for 60 minutes. Stirring every 10 minutes.
After 60 minutes, the tomatoes should be falling apart. Remove them from the heat and let cool in the skillet for about 20 minutes before serving. Adjust salt and pepper before serving if desired.
Cook the pasta until al dente. Reserve about ¾ cup of the pasta water once cooked and add to the tomato confit, stir everything into the pasta. Adjust seasoning as needed and serve with chopped chives.