Place walnuts into a bowl and cover with milk; soak in the refrigerator for 3 to 4 hours or overnight.

Drain walnuts and place into a food processor. Add queso fresco, sour cream, sugar, and cinnamon. Puree until completely smooth. Add milk as necessary to make the sauce creamy. Set sauce aside.

Set an oven rack about 6 inches from the heat source and preheat the broiler. Line a baking sheet with aluminum foil.

Place poblano peppers onto the prepared baking sheet. Broil until skins blacken and blister, about 10 minutes, turning peppers halfway through.

Remove peppers from the oven and seal in a plastic resealable bag. Allow to sit and steam for 15 minutes.

Carefully remove skins from peppers using a spoon or fingers. Cut a slit down the side of each pepper and remove seeds and veins. Set peppers aside.

Heat a skillet over medium heat. Saute chorizo for 2 to 3 minutes. Add squash blossoms and cook until chorizo browns and blossoms wilt, about 5 to 7 minutes. Stir in black beans and corn, cooking for 1 to 2 more minutes. Mix in Mexican cheese.

Carefully stuff peppers with the chorizo mixture. Do not overstuff to ensure peppers can close completely.

Separate eggs into two bowls. Mix 1 tablespoon flour into yolks to form a paste. Whisk egg whites until stiff peaks form, then fold them gently into the yolk mixture.

Dredge stuffed peppers in 1 cup of flour. Coat them completely. Dip flour-coated peppers into the egg mixture, ensuring they are fully covered.

Heat vegetable oil in a deep-fryer or deep pan to 350°F (175°C). Deep-fry peppers until golden, about 2 to 4 minutes. Transfer to a rack to drain.