In a small skillet, toast the black sesame seeds over medium-low heat until fragrant. Be very careful not to burn these guys - the darker the nut/seed, the easier it is to char further.
Transfer the sesame seeds to a small food processor and pulse until the mixture resembles a fine black sand.
Add the coconut milk, banana, maple syrup and tahini, if using. Puree until very smooth.
Transfer to a jar or cup(s), garnish with more black sesame and enjoy!
The tahini gives the ice cream that extra something something--the way peanut butter gives desserts that nutty background taste that ground peanuts never could. It's also slightly bitter. If you need more maple syrup, adjust to taste.