Slice tomato and season with salt, pepper and red pepper flakes if using.
Add bacon to skillet and cook on medium heat for about 4 min per side or until desired crispiness. Transfer to a paper towel lined plate.
If you are making sriracha mayo (versus buying it premade) combine mayo and sriracha in a bowl and mix until smooth.
Coat ciabatta in olive oil and cook for 2-3 min per side until golden brown. Remove from pan and set aside.
Spread sriracha mayo on ciabatta, then add avocado, slices of tomato, bacon, and lettuce. Close sandwich and enjoy!