DIRECTIONS
Preheat oven to 450 degrees.
Cut one lemon into thin slices and set aside.
In a small saucepan combine bourbon, soy sauce, brown sugar, garlic, and zest and juice of one lemon.
Bring to a boil and simmer until thickened; 5 to 10 minutes depending on desired thickness of glaze.
Turn off heat and cover with lid to keep warm.      
Preheat large cast iron skillet over medium-high heat.
Pat tuna dry with paper towels and season with salt and black pepper.
Add 1 TBSP. olive oil. When oil is hot but not smoking add tuna skin-side down and place 2 to 3 lemon slices fanned over top.
Sear for 2 minutes, then transfer pan to over and bake for 10 minutes.
Reheat glaze on low; drizzle over tuna and top with cilantro.
Serve immediately.