Wash and cut the stems off of the portobello mushrooms. Heat a frying pan with olive oil over medium and fry mushrooms covered for 3-5 minutes per side or until soft and tender. Remove and set aside.
Cook bacon to desired crispiness. Remove and wrap in paper towels to absorb grease.
In a large mixing bowl combine ground beef, sea salt, pepper, garlic powder, pepper flakes, paprika, olive oil, egg, and almond flour. With clean hands, knead the mixture until well combined. Shape the mixture into 1/2 inch thick patties, or thinner, poking a whole halfway through the middle using your thumb (this will help keep the burgers flat when cooking).
Cook burgers 5-6 minutes per side or until browned through. Let stand for just under 5 minutes and place between portobello mushrooms. Top burgers with the bacon, red onion, tomato, romaine lettuce, sautéed jalapeños, and mustard. Toppings are all optional. Serve with a balsamic salad or vegetables of choice and enjoy!