The procedure:

Place oil into deep fryer according to the manufacturer’s instructions and preheat to 375F. If you don’t have a deep-fryer, heat up enough oil in a thick-walled pot (at least a depth of 3 inches, I’d say) to a temperature of 375F. As in all situations where there’s a big vat of hot oil involved, make sure you keep an eye on it!

In a medium bowl, whisk together the all-purpose flour, glutinuous rice flour, baking powder, 1 teaspoon granulated sugar and salt. Add additional spices, if using. Add the mashed sweet potato flesh and knead until you get a moist, soft dough. If the dough is too wet, add flour one teaspoon at a time until you get a workable dough. If your dough is too dry, add some lukewarm water; trust your instincts as different sweet potatoes vary in water content. Try not to over-knead though, as overcompacting and overworking the dough will result in tough donuts.

Divide the dough into 5 portions, about 35g each. Use your finger and thumb to poke a hole in the middle, making a cute little donut. You are free to roll out the dough and punch them out if you have donut cutters as well.

Place some granulated sugar in a shallow bowl and have it ready. Place a rack with a paper towel underneath it for the donuts that come out of the fryer. Having tongs ready right about now is good too.

Test your oil to see if it’s hot enough; a great test I’ve always used is to stick a wooden chopstick into the oil. If bubbles form immediately and quickly around the chopstick, the oil is ready. If the bubbles are slow to form, it’s definitely not hot enough. Fry the donuts, two to three at a time, making sure not to crowd the pot. Adding them all at once will make the temperature of the oil drop too much, resulting in oily donuts. Fry until golden brown and cooked all the way through, about 6-7 minutes. Using tongs or a slotted spoon, drain the donuts and immediately drop them into the shallow sugar bowl, turning them to coat. Place on the rack to cool briefly and continue to fry the rest of the donuts.

As with all fried goods, enjoy these donuts as soon as possible as their deliciousness is inversely proportional to the time out of the fryer.

The procedure:
Preheat the oven to 250 degrees F. Place the raw walnuts in a shallow pan and roast for 30 minutes, stirring once in a while so the nuts roast evenly. Keep an eye on them so they don’t burn and turn bitter. Once it starts to get fragrant, it’s almost ready. Remove the pan from the oven and let the walnuts cool.

Meanwhile, in a large pan, pan roast the black sesame seeds over medium-low heat, stirring continuously. Roast for about 10 minutes, or until the seeds start to smell fragrant. Turn off the heat immediately and remove the pan to a cool place. Grind the seeds in a spice grinder, coffee grinder or if you have a Vita-Mix/Blendtec, until you have a wonderfully fragrant powder. Make sure to scrape down the sides periodically so that you have a uniform grind.

By the way, grinding the seeds to a powder before making the butter ensures that you have a creamy end product; trying to grind the whole seeds with the walnuts will only result in a grainy, hulled butter. If this is what you prefer, by all means go for it

Once the black sesame powder and walnuts are cooled, place them in the bowl of your food processor along with the sea salt and sugar. Grind until creamy; this should only take about 2 – 3 minutes; it will first ball up, then loosen as the walnuts release their oils. Keep going until your tahini is whipped and smooth.

Scrape into a sterilized glass jar; allow to cool (it will be a bit warm from the processing) before putting on the cap and storing in the refrigerator. I’ll wager it’ll keep for at least two weeks, but keep an eye on it as walnut oils tend to go rancid quite easily.