1/3 cup sweet onion, chopped
1/2 cup whole or 2% milk
3/4 cup pepper Jack cheese, freshly grated
4 ounces processed cheese, such as Velveeta
1/3 cup canned diced tomatoes with green chilies (such as Rotel)
In a pan, heat onion and a splash of oil on medium-low about 5 minutes, until softened. Add milk and heat another 5 minutes. Add pepper Jack cheese, and whisk while it melts. Then, add processed cheese, and whisk until fully melted. Stir in tomatoes, then heat 5 more minutes.