Heat oil in a large Dutch oven, over medium heat, until shimmering.
Add peppers, onion, garlic, cumin, bay leaves, a large pinch of salt and a few grinds of black pepper.
Cook, stirring occasionally, until vegetables are completely tender and the mixture is not runny or watery; about 30 minutes.
Adjust heat as necessary to prevent any browning.
Remove from heat and allow mixture to cool.
Store in sealed containers, in the refrigerator, for up to 1 week.