Place a medium saucepan over medium heat, add the butter, and allow it to melt completely.

Add the finely diced white onion and cook for 2–3 minutes, stirring, until the onion is soft and translucent.

Stir in the minced chipotle peppers and adobo sauce; cook for 30 seconds to 1 minute until fragrant.

Pour in the heavy cream and whole milk, stirring to combine and gently warm the mixture.

Add cumin, smoked paprika, kosher salt, and black pepper; stir well to distribute the spices.

Reduce heat to medium-low. Add shredded white cheddar in small handfuls, stirring continuously until each addition is fully melted.

Add shredded Oaxaca or mozzarella the same way, stirring until the queso is smooth and fully combined.

Stir in the lime juice, then taste and adjust seasoning with additional salt, pepper, or adobo sauce if desired.

Serve the queso warm, garnished with cilantro, jalapeño slices, or crispy bacon bits if using. Keep over low heat or in a slow cooker on warm for serving.