Chop the onion, garlic, tomato and green chili into small pieces. This helps them cook evenly and quickly. Keep all ingredients ready before starting. It makes the cooking process smooth and stress-free.

Heat butter in a saucepan over medium heat. Add the chopped onion and cook until soft and light golden. Then add garlic and cook for one minute. Stir gently to avoid burning.

Add the diced tomato and green chili to the pan. Cook for about three minutes. The mixture will soften and release a rich aroma. Stir often so everything cooks evenly.

Slowly pour the milk into the pan while stirring. Mix well with the cooked vegetables. Let it warm gently on low heat. Do not let it boil too fast to keep texture smooth.

Add cheddar and Monterey Jack cheese little by little. Stir continuously until fully melted. Keep heat low during this step. This prevents the cheese from becoming grainy or clumpy.

Add salt, black pepper and paprika. Mix everything well. Taste the queso and adjust seasoning if needed. The flavor should be creamy, slightly spicy and well balanced.

Remove from heat once the queso is smooth and creamy. Pour into a serving bowl. Garnish with fresh cilantro. Serve warm for the best taste and perfect dipping texture.