Sweet Potato and Avocado Yaki Onigiri

SWEET POTATO & AVOCADO 
YAKI ONIGIRI

Garrett and I are getting up early tomorrow to drive out to Flint, MI for Christmas, so we're going to need some good car trip snacks for the five-hour haul.  Perhaps Japanese finger foods don't immediately come to mind on this occasion (road trips or Christmas), but based on my experience they should.

Onigiri are the perfect to-go food: balls of sticky rice with a tasty filling that comes with a built in seaweed handle.  They are a staple at Japanese convenient stores and food kiosks especially for that reason.  I trained across Japan a few years ago, and always embarked with onigiri of a mysterious flavor.  Since I don't read Japanese, I experienced a wide range of fillings - from just a little teriyaki, to red bean paste, smoked salmon, and once in a while, some offensive fermented root vegetable.  But really, the star of the show with onigiri is the slightly sweet and slightly vingary sticky rice.  Most onigiri from an average market wouldn't be grilled, but yaki ("grilled") onigiri has the extra pleasure of crunchy bite leading to the warm, sticky filling.

Besides road trips or picnics, onigiri makes a great party finger food.  If you've ever been tempted to make sushi but found all the chopping and rolling a hassle, onigiri make an excellent alternative.  The onigiri pictured here would be a little big as party hors d'ouevre, but could be scaled down to your liking.  Try out different fillings (like variations of your favorite sushi rolls) for your New Year's Eve party.

Ingredients (makes 5-6 large onigiri, depending on size):

• 1 1/2 cups white sushi rice
• 1 tbsp. sugar
• 2 tbsp. rice vinegar
• 1/2 tsp. salt
• 1/2 sweet potato
• 1 oz. avocado, smashed or diced
• 1 sheet seaweed paper/nori
• 3 tbsp. teriyaki sauce (low-sodium & gluten-free)
• 1 tbsp. sesame oil
• 1 tbsp. honey
• 1/2 tbsp. freshly ground ginger
• 1 tbsp. sesame seeds

Preheat the oven to 375 degrees.  Bring the rice and 2 cups of water to a low boil on the stove top, then lower the heat and cover for 20 minutes until rice has absorbed all the water and is sticky.  Remove from heat and let sit, covered, for ten minutes.

While the rice cooks, prepare the sweet potato filling by peeling the potato, and cutting it into 1/4 inch slabs.  Square the slabs down to size, depending on what you will use for your onigiri mold.  I used a standard 1-cup measuring cup, and needed about 1.25" x 1.25" squares.

Mix together the teriyaki sauce, sesame oil, ginger, and honey in a bowl and toss the squares of sweet potato to coat lightly.  Save the remaining sauce for after the sweet potato is cooked.  Spread the squares on a baking sheet and bake for about 20 minutes, flipping halfway through.

When the rice has cooled a bit, dissolve the sugar and salt in the rice vinegar and add the solution to the rice.  Fluff with a fork until the rice is evenly coated.  

Meanwhile, cut the nori into 1 1/2 inch strips for later, and prepare the avocado for filling.  

When the rice and sweet potato are both cooked and cooled, you are ready to assemble the onigiri.  While you don't need to use a mold and can shape the unigiri by hand, for an even look use a cookie cutter or measuring cup.  I lined a 1-cup measuring cup with plastic wrap for easy removal.

With wet hands, press about 2 tbsp. of rice into the mold.  Layer in a piece of sweet potato dipped in the remaining teriyaki sauce, along with a piece of avocado.  Wet your hands again and top with another 2 tbsp. of rice.  Flip and tap onto a plate, pulling the plastic wrap a little to remove.

Once you've formed all the onigiri, sprinkle with sesame seeds and grill in pan with just a little sesame oil.  Each side should brown in about 3-4 minutes on high heat.  

Wrap with a piece of nori and dip in teriyaki to enjoy.