Preheat oven to 450°F (232°C)
Line a baking sheet with parchment paper or foil
Rinse sweet peppers and pat dry
Cut peppers in half lengthwise and remove seeds and stems
Place peppers cut-side down on the baking sheet
Drizzle lightly with olive oil and season with salt
Roast 15–25 minutes, until skins blister and peppers are tender
For extra char, broil 1–3 minutes, watching closely
Transfer peppers to a bowl and cover with a lid or plastic wrap
Rest 10–15 minutes to loosen skins
Peel off skins (optional but recommended) and discard seeds and membranes
Slice or leave halves as desired
Serve warm or cool, or store in an airtight container in the refrigerator up to 4–5 days