Preheat the broiler to high or the grill.: The air will warm quickly, and you should be able to hear a faint hum as the broiler element powers up or feel a steady heat on the grill. High direct heat is important because it chars the pepper skins quickly while preserving their sweet interior. If your broiler has hotspots, rotate the pan halfway through broiling to avoid overly dark patches. A common mistake is using low heat which results in limp, pale peppers rather than slightly blistered and aromatic ones.
On a baking sheet, lay the mini peppers in a single layer. They usually have no seeds, so once the tops are cut off they're ready for the filling.: When the peppers are spread out evenly you give each one access to the broiler sizzle or grill smoke. You want to see space between them so air circulates and they char, not steam. The visual cue is little pools of oil and the peppers starting to wrinkle at the edges. If they crowd, they will sweat and stay raw inside; avoid overcrowding to prevent steaming instead of charring.
Sprinkle a pinch of salt and olive oil over the peppers and toss gently. Keep them always in a single layer.: As the olive oil glazes the skins, they take on a subtle sheen and the salt draws out natural sweetness, enhancing caramelization. Toss until each pepper has a light coating, you should almost see them glisten. A heavy hand with oil can lead to greasy char and flare ups on a grill, so use just enough to coat.
For the feta filling: Mix all the ingredients in a medium-sized bowl.: Mix all the ingredients in a medium sized bowl : As you combine the crumbled feta , sour cream , minced garlic , lemon zest and juice, chopped herbs , minced scallions , olives, spices and oil, the aroma will lift—bright citrus, salty cheese, and herbaceous green notes. Mixing by hand helps you control texture, leaving small chunks for interest. A binder like sour cream smooths the mixture; if it seems dry, add a touch more. Avoid overworking the cheese which can become gluey.
For the feta filling: Mix all the ingredients in a medium-sized bowl.: Mix all the ingredients in a medium sized bowl : When the ingredients fully integrate you should taste a balanced combination of salty, tart, and herby flavors. The mouthfeel will be creamy with little olive brine pockets and herb flecks. Chill briefly if the mixture feels too loose, this firms it up making spooning simpler. A common oversight is skipping a taste test, which can leave the filling under seasoned.
Use a teaspoon, place a teaspoon size filling inside each of the mini peppers. Make sure NOT to overfill the peppers.: As you spoon the filling you will feel the pepper giving slightly as it fills, and the small mound should sit just at the rim without spilling over. The visual cue is a neat rounded top of filling. This size ensures every bite stays balanced. Overfilling causes leaks during cooking and makes them hard to eat, so resist packing more than a teaspoon.
Any remaining feta mixture can be stored in the fridge for a week minimum—so long as it has no tomatoes **.: Stored in an airtight container, the flavors meld and the filling firms a little, improving spreadability. You will notice the aroma deepen after a day. If you included tomato , the extra moisture shortens storage life, so omit tomatoes for long storage. Keep an eye out for off smells or separation which indicate the mix is past its prime.
Place the pan in the broiler over and broil for 5-7 minutes until peppers are charred and tender.: As they cook, you should see dark flecks appear on the skins and hear a subtle pop as juices release. The cheese will warm and develop tiny golden spots where it meets heat. The peppers should be tender when pierced with a fork but still hold shape. Broiling too long will collapse them into limp softness, so watch closely in the final minute.
If grilling, place the pepper on the grill and grill for 3 minutes per side.: On the grill the skins pick up smoky notes and those attractive grill lines. You will hear soft hisses as juices meet hot grates, and the scent becomes pleasantly charred. Turn gently with tongs so the filling stays inside. A common error is placing them directly over a very hot flame which can blacken and dry them; aim for medium high heat.
Serve right away or chill in the fridge for up to 3 days.: Served warm, the filling is creamy and slightly gooey, and the peppers release a fragrant roasted aroma. Chilled, the flavors are more measured and the filling firms for tidy bites. If refrigerating, cover the tray or transfer to an airtight container to protect against drying. Reheating briefly under the broiler refreshes char and softens the filling if you prefer them warm.