Preheat the oven to 400 degrees.
Line a small baking sheet with aluminum foil and arrange the bacon in a single layer on the tray.
Cook the bacon for 12-18 minutes, depending on thickness, until golden and crispy.
Remove bacon from the oven and drain on paper towels. Reserve the tray with the bacon fat.
When cool enough to handle, crumble the bacon and set aside.
While bacon is cooking, make avocado cream by scooping the flesh from the avocado. Thoroughly mash the avocado in a small mixing bowl.
Add the sour cream and mix until smooth. Set aside.
Cut the mahi mahi horizontally into strips of about ¾” thickness. Season with salt and pepper.
Heat the vegetable oil and bacon fat in a sauté pan over medium high heat. Add the mahi mahi and cook for 1 ½ minutes or golden on the bottom. Turn the fish and cook for an additional 1-2 minutes, until just cooked through. Add the crumbled bacon and toss briefly before removing from heat.
Transfer the bacon and mahi mahi to a serving plate.
To soften the tortillas, place them in a dry skillet over medium heat for about 30 seconds on each side. (For super-tasty tortillas, heat on a grill or open flame until brown spots appear.)
Smear the inside of a warm tortilla with the avocado cream. Put a little lettuce in the bottom of each tortilla then top with two or three strips of fish and a sprinkle of bacon. Add your desired amount of additional toppings before serving.