The typical church lunch in Japan is curry rice, which only involves one pot and a rice cooker. The curry is nothing like what they serve in the subcontinent, but it is comfort food.
While we did do the traditional potluck for the Loves' farewell (see post below), our spur of the moment choice on a sunny day is the terrace at Triton Square, and food from the food court, or the convenience store or grocery store, which both sell obento box lunches.