Roast the poblanos. Place the peppers on a broiler-safe baking sheet. Broil for about 4–5 minutes per side, turning as needed until the skin is blistered and charred. Watch closely. Transfer to a bowl, cover, and let steam for 5–10 minutes. Peel off the loosened skin, remove the stem and seeds, and finely chop.
Cook the onion. Heat the olive oil in a medium saucepan over medium heat. Add the onion and cook for 8–10 minutes, stirring occasionally, until softened and lightly golden. Reserve a little onion and poblano for topping.
Make the base. Reduce the heat to medium-low. Add the butter and let it melt, then stir in the garlic and cook for 30 seconds. Whisk in the flour and cook for 1 minute.
Add the liquids. Slowly whisk in the beer, followed by the milk, until smooth. Bring to a gentle simmer over medium heat and cook for 2–3 minutes, whisking often, until slightly thickened.
Add cream cheese and seasonings. Reduce the heat to low. Stir in the cream cheese until smooth, then add the chopped poblano, Dijon, Worcestershire sauce, paprika, and black pepper.
Melt the cheese. Add the Land O Lakes® CoJack and Land O Lakes® Habanero Jack a handful at a time, stirring until each addition melts. Keep the heat low and avoid boiling. Stir in a splash of milk if needed to reach your preferred dipping consistency. Taste before adding salt.
Serve warm. Top with the reserved onion and poblano, if using. Serve with tortilla chips, pretzels, or crusty bread.