Heat oven to 400°F (200°C). Line a baking sheet with parchment and set a wire rack on top.
Slice jalapeños in half lengthwise and scrape out seeds/membranes with a spoon.
In a bowl, mix cream cheese, bacon, green onion, garlic, salt, black pepper, and 7 oz (200 g) cheddar until combined.
In a skillet over medium heat, warm olive oil. Add panko and stir until golden. Remove from heat.
Fill each jalapeño half with the cream cheese mixture and smooth the top.
Arrange on the rack. Sprinkle with remaining 1 cup (100 g) cheddar, then top with toasted panko and a little chives.
Bake 12–15 minutes until hot and melty. Broil 1–2 minutes for extra color if desired. Rest 5 minutes before serving.