place bacon on a foil lined cookie sheet and bake at 350 for 20-30 minutes until crispy. in large pot, boil potatoes in hot salted water for about 15-20 minutes until JUST fork tender. meanwhile in small to medium saucepan place 1/2 stick butter and the broccoli, onion, celery, carrot and onion. start on a medium heat and stir often to coat vegetables with the melting butter.
cut chicken up into very small dices and add to the saucepan with the vegeatbles and continue to cook until no longer pink.
drain potatoes very well and rinse quickly w cold water to remove any foam or starch. drain bacon on paper towels.
rinse the large pot and add to it the rest of butter and let melt, add flour and whisk until blended and starts to smell nutty and becomes golden color. add milk and broth and whisk vigorously to combine.
add the entire sauce pan ingredietns to larger pot. put the potatoes back inches salt pepper and garlic powder next.
add velveeta and let simmer on a low heat, stirring often to prevent scorching bottom of soup. once velveeta melts add cheddar and continue until it is melted. taste and adjust seasonings.
serve with 2 slices bacon crumbled on top each serving.