- Mix all topping ingredients and preheat broiler set with top-middle rack

- Bring water to boil for pasta in a large sauce pan add 1 t. salt to water

- add asparagus and pasta and cook until pasta is still just shy of aldente

- drain in colander and set aside

- While pasta is cooking heat a dutch oven on med heat, add bacon and cook till crispy

- remove bacon to paper towel on plate

- remove all but 1T grease.

- Add onion to pan and cook till tender about 5 min

- Add butter and stir till foamy

- Wisk in flour and continue to stir until golden brown

- gradually wisk in evaporated milk and broth

- bring to boil over med-high heat

- simmer for 5 min or till thickened stirring constantly

- Stir in cheese and 1/2t salt and pepper

- remove from heat wisk in egg yokes

- return pasta, asparagus bacon, tomato and chives to pot

- stir and transfer into a broiler safe casserole dish

- sprinkle with topping and broil until browned 3-5 min