Preheat oven to 200℉.

Cook bucatini in salted water until al dente (reduce time recommendation on the package by 1-2 minutes,) drain, keep in a bowl.

Generously salt and pepper chicken. Put oil in a large pot over medium-high heat and brown chicken on both sides to a nice golden-brown color. You may need to do it in two batches. Transfer chicken to a bowl. Add onion to pot and sauté for about 6 minutes, scraping the bottom of pot to release all the good flavor. Add tomato paste and spices to onion, stir and cook for another minute. Remove pot from heat, pour onion and fat on cooked bucatini, add 1 teaspoon kosher salt and mix well.

Line bottom of pot with potato slices, sprinkle with salt. Top with about ¾ of the bucatini, pressing them down. Arrange chicken on the noodles, arranging raw eggs between them carefully, and top with the rest of the bucatini. Add ½ cup boiling water. Cover tightly with aluminum foil (make sure the aluminum foil does not touch the noodles. If it does, first line the noodles with parchment paper and only then with the foil). Then cover with lid. Bake overnight or for 6-8 hours or longer. Let rest for 10 minutes before serving.