To begin, preheat your oven to 450 degrees. Line a baking sheet with aluminum foil or parchment paper for easier cleanup.
Wash and dry your red peppers.Place the red peppers on the baking sheet and put them in the oven for about 45 minutes. Halfway through, make sure to turn your peppers to the side. You will know it is time to flip them when the tops and bottoms have charred.Once they have fully roasted, take them out and set aside to cool.
Once they are cool enough to handle, peel the peppers. The skin should come off quite easily. Using a small knife cut off the stem and remove all the seeds and membrane inside.
Place the peeled peppers in a jar or Tupperware with all their juices.
Notes
You can roast just one pepper for a specific recipe or you can roast a bunch and keep them in your fridge covered for up to two weeks.