Heat butter in a medium frying pan over medium heat. Add onions and season with salt and pepper. Cook, stirring occasionally, until very soft and starting to brown, about 10 minutes. Remove from heat and let cool completely.

Combine onions, cream cheese, chipotles, and salt in the bowl of a food processor fitted with the blade attachment. Pulse until completely combined. Transfer to a medium bowl and add Manchego cheese. Fold in cheese until incorporated. If cheese is too soft to shape into a ball at this point you can refrigerate for a little bit until is hardens up.

Combine chives, pumpkin seeds, and poppy seeds on a small plate.

Using wet hands form cheese into a ball shape and holding the ball over the plate, sprinkle on the chive topping until cheese ball is completely covered. Place on serving tray and place in refrigerator until solid, about 30 minutes.

Serve with crackers, celery, cucumbers, or tortilla chips.