The Best Queso

Ingredients (13)

• 2 tablespoons unsalted butter
• 1 medium jalapeño or 2 tablespoons drained jarred jalapeños (both optional)
• 1 small-to-medium red onion, chopped 
• 1/2 teaspoon fine salt, divided
• 3 cloves garlic, pressed or minced
• ¾ cup whole milk, more to thin if desired
• 8 ounces cream cheese, cut into 1-inch cubes
• 8 ounces mild cheddar cheese, shredded (about 2 cups)
• 8 ounces Monterey Jack or pepper jack cheese, shredded (about 2 cups)
• 1 cup quartered cherry tomatoes, diced ripe tomatoes or canned drained diced tomatoes
• Several dashes of your favorite hot sauce, such as Cholula
• 2 tablespoons chopped cilantro
• Tortilla chips or warmed tortillas, for serving