In a large non-reactive saucepan, heat olive oil over medium heat. Add onion, shallot, and garlic and cook for 2-3 minutes, until translucent.
Add cumin, coriander, chile flakes, orange zest, fennel seeds, salt, pepper, and mustard seeds. Cook, stirring frequently, until mustard seeds begin to pop, about 1 minute.
Add tomato paste and stir until oil starts to separate, about 30 seconds. Stir in sugar and stir until it starts to bubble, about 1 minute. Add vinegar and allow mixture to combine, stirring for about 1 more minute.
Turn heat down to low and add the tomatoes. Continue to cook, stirring frequently, for about 25-30 minutes. The confiture should deepen in color and flavor.
Recipe by Things I Made Today at https://www.thingsimadetoday.com/2018/12/22/tomato-confiture-inarguably-best-sauce-ever/