Place the potatoes in a saucepan and add water to cover. Bring to a boil over high heat. Cook until the potatoes are easily pierced with a fork, 15 to 20 mins. Drain.

Meanwhile, bring the lentils and 3 cups water to a boil in a pot. Cook until the lentils are tender but not disintegrating, 15 to 20 minutes. Drain.

Place the potatoes in the bowl of a stand mixer fitted with the paddle attachment. Mix until mashed with no lumps. Add the berbere, tomato paste, onion powder, garlic powder and 1 teaspoon salt. Continue to mix until combined.

Check the dough for consistency; it should be moist and pliable but not wet. To test, roll a bit of dough between your palms: If it crumbles, add some vegetable oil until it holds together. If it's sticky and clings to your hands, add instant potato flakes until it holds together.

Finally, taste for salt. The filling should be slightly saltier than you prefer so that the flavor stands up to the dough.

To assemble the pierogi: On a well-floured surface, roll out a ball of Vegan Pierogi Dough the size of a large orange into a rectangle about 1/8-inch thick. Cut out 3-inch rounds of dough (a pint glass will do).

Place 2 tablespoons of filling into the center of each round and fold the rounds in half. Take care to make sure all the air pockets are pressed out of the pierogi. Crimp the edges with a fork or your fingers.

Boil the pierogi for 3 minutes, then brown in a skillet. Serve with caramelized onions and sour cream.

Vegan Pierogi Dough:

Add the flax seeds and 2 cups water to a saucepan. Bring to a boil over high heat. (Keep an eye on the pan: Once the mixture starts boiling, it will foam up and boil over quickly!) As soon it starts to boil, reduce the heat to a simmer and cook for 10 minutes. Strain the resulting gel through a nut-milk bag or fine-mesh sieve. Discard the seeds and refrigerate the gel until cool.

Mix the instant mashed potatoes with 1/2 cup water and let stand 2 to 3 minutes.

Add the flour, water, baking powder, salt, 1 cup flax gel and 3/4 cup of the instant potatoes to the bowl of a stand mixer fitted with the dough hook. Mix on low speed until the dough is smooth, elastic and slightly tacky, about 8 minutes. Turn the dough out into a bowl and cover with a clean, damp kitchen towel. Let rest in the refrigerator for 30 minutes.