Optional: you can also try adding julienne cut carrots, red cabbage, sprouts, or scallions
Rice: Cook rice by instructions on package. When finished, do not stir rice and allow it to cool. This will make for a stickier to hold everything together.
Deseed: Cut each cucumber in half and remove seeds with either a small spoon or knife to create a long, hollow tube (see pictures).
Stuff: Spoon in a small amount of rice, then compress towards one side of the tube. Gently insert a slice of avocado and a few slices of pepper, then add more rice to fill gaps, compressing and adding more rice until packed full.
Slice: With a sharp knife, slice cucumber into 1/2 inch thick pieces. If you start to notice the filling is loose as you cut, stuff in more rice and peppers where needed.
Serve: Serve with soy sauce or spicy mayo*.
*To make spicy mayo, mix 1 Tbsp mayo and 1/2 tsp sriracha.