Prep Ingredients: Dice the onion and jalapeños, and chop the cilantro. Prepare pico de gallo if using.
Sauté Aromatics: Heat oil in a medium saucepan over medium heat. Add onions and jalapeños, sautéing for 3-4 minutes until softened.
Heat Half and Half: Pour in the half and half, stirring constantly. Heat until small bubbles form around the edges—do not boil.
Melt the Cheese: Gradually add sliced cheese, stirring until fully melted and smooth (about 5-7 minutes).
Add Cilantro: Stir in chopped cilantro for a burst of freshness.
Serve: Transfer queso to a serving bowl, garnish with pico de gallo if desired, and serve immediately with tortilla chips or your favorite Tex Mex dishes.