Chili Con Queso

• 1/2 medium onion
• 1 T butter
• 1 Ib Velveeta cheese, cut in 1/2 inch chunks
• 1 or 2 cans Rotel tomatoes, drained and chopped
• 1/8 to 1/4 cup picante sauce

Saute onion in butter until soft. Melt cheese and add onion and remaining ingredients. Heat (I make this in the microwave) and serve warm with chips.