Chili con Queso with Chicken (Similar to Carlos O'Kelly's)

INGREDIENTS

• 2 tablespoons butter
• 1 medium tomato, diced
• 1 tablespoon chopped onion, or to taste
• 1 clove garlic, minced
• 2/3 (1 pound) package processed cheese, cubed
• 8 ounces sour cream
• 2 small cooked skinless, boneless chicken breast halves, shredded
• 1/2 (4 ounce) can green chiles, chopped - or to taste
• 2 tablespoons salsa
• 1/4 teaspoon seasoned salt
• 1/4 teaspoon dried oregano