In a large skillet over medium heat, melt butter and add diced onion. Cook, stirring often, until soft; 3-4 minutes. Crumble in chorizo sausage and cook until no longer pink. Drain grease from the pan, leaving about a tablespoon.

Add flour and stir to coat. Cook for one minute.

Whisk in milk and simmer until thickened; about 3-4 minutes.

Turn heat to medium-low. Stir in 8 ounces of cream cheese until melted, then add tomatoes, corn and 6 ounces of Horizon Organic Cheddar Cheese (reserve a small amount for topping, if desired). Stir until melted and combined, and continue to cook, stirring often, over medium-low heat until cheese is melted and bubbly. Season with salt if desired.

Remove from heat and garnish with diced tomatoes, fresh chives and reserved cheese, if desired. Serve hot with tortilla chips for dipping.