Prepare sushi rice, and allow to cool to room temperature before assembling rolls.

Prep Nori: You can use whole sheets of Nori for large sushi rolls, or break nori sheets in half to make smaller California rolls. To do so, stack two or three sheets together and fold the nori in half, the two short ends coming together. Press to crease it, and then gently pull the sheets apart.

Wrap Bamboo Mat in two long pieces of plastic wrap to tightly cover it from both sides. This will keep it clean and prevent sushi rice or nori from sticking to it.

Make spicy tuna filling: Chop the tuna into small pieces. Add to a bowl. Add sesame oil, mayo and sriracha and mix to combine.

Assemble: Place bamboo mat on a counter in front of you, with the sticks parallel to you. Place a piece of nori on the mat, dull side up, with the long side parallel to you.

Place a small bowl of water next to your work station. Scoop roughly 1/2 cup or 1 cup (for small or large sushi rolls) onto the nori. Use wet fingers to gently move the rice, spreading it into an even layer across the nori (don’t smash it), but leave about a half inch of seaweed clear with no rice, at the top end.

Add filling: Spoon some spicy tuna mixture on top of the rice, in a line slightly off center, closest to you. (Add two thin pieces of cucumber if desired).

Roll: Use your fingers to gently spread some water on the top of the seaweed that doesn’t have rice on it. Then lift the end of the bamboo mat closest to you up and over the ingredients. Continue to roll, pulling the bamboo mat away from you, until completely rolled. Press both hands on top of the bamboo mat and squeeze the sushi roll gently beneath it, to make sure it hold firmly together.

Cut and serve: Cut roll into 6 portions and top with chopped green onion. Serve with sides of soy sauce and pickled sushi ginger. Optional: drizzle rolls with sriracha mayo, eel sauce, or top with fried onions or micro greens.