In a small to medium saucepan melt the butter and add the garlic and green onions and saute for 1 minute, over low heat, until just soft.
Add the chilli powder and cook for 30 seconds.
Stir in the sour cream and cheeses and cook for about 3 minutes, until cheeses are melted and the dip is warm. Add the chilli and coriander, stir and serve immediately.
Note* You can also make your own Mexican chilli powder / seasoning by combining ¼ teaspoon of cumin, ¼ teaspoon paprika, a pinch of garlic powder, pinch of oregano, a pinch of dried chilli flakes and a pinch of cayenne pepper.
Note** The Kraft processed cheddar is found in Australian supermarkets with the sandwich spreads and cream cheese, in a blue box (also Dairy Lea brand). Velveeta is more commonly available in the USA. Both work well with this recipe.