Rinse 1 1/2 cups wheat berries in cold water until the rinse water runs clear. Place the rinsed wheat berries in a bowl and cover with lukewarm water so the water is about 2 inches above the berries. Soak overnight (8–12 hours).
The next day, drain the soaked wheat berries. Transfer them to a medium heavy pot and add 4 1/2 cups of milk (or water, if you prefer; milk tastes better). Bring to a boil over high heat.
When the liquid reaches a boil, reduce heat to low, cover the pot, and simmer gently until the wheat berries are very tender, about 3 1/2 to 4 hours. Stir occasionally to prevent sticking. If the liquid level drops and the berries are exposed, add more milk to keep them submerged.
While the wheat berries cook, prepare the poppy seeds: place 3/4 cup poppy seeds in a fine-mesh sieve and rinse thoroughly. Transfer the rinsed poppy seeds to a medium saucepan and add about 3 cups water.
Over medium heat bring the poppy-seed mixture to a gentle simmer (do not boil). Turn off the heat, cover, and let sit 30 minutes. After 30 minutes, return to a gentle simmer again (do not boil), turn off the heat, cover, and let sit another 30 minutes.
Drain the poppy seeds well using a colander or by covering the pot and using several layers of cheesecloth over the lid to catch stray seeds. Grind the drained poppy seeds using a food grinder with a fine plate or in batches in a clean coffee grinder until finely ground. Set the ground poppy seeds aside.
Preheat the oven to 350°F. Spread 2/3 cup slivered almonds in a single layer on a baking sheet and toast in the oven for about 5 minutes, watching closely so they do not burn. Remove the almonds and reduce the oven temperature to 325°F.
When the wheat berries are very tender, drain the cooking milk into a glass measuring cup. Reserve 1/2 cup of the cooked milk and discard the remaining cooked milk.
In a small bowl, combine 1/2 cup honey with the reserved 1/2 cup cooked milk and stir until smooth.
In a large mixing bowl, combine the cooked wheat berries, the ground poppy seeds, 1/2 cup raisins, 2/3 cup chopped dry apricots, the toasted 2/3 cup slivered almonds, the honey-milk mixture, and 1/8 teaspoon salt. Mix thoroughly to combine.
Transfer the mixture to a casserole or pie dish and bake uncovered at 325°F for 20 minutes.
Remove the kutia from the oven, cover with foil, and let it rest 15 minutes before serving. Serve warm or cold. Store in the refrigerator; kutia will keep up to about 2 weeks.