Puree the corn kernels with the milk and butter in food processor; then add the
sugar, salt and 1/3 cup cornmeal; blend quickly. Add more cornmeal only if the batter
seems too liquid. Transfer to a bowl. Wash and dry the processor bowl.
Chicken Sofrito Filling: With the food processor running, drop the chiles and
garlic through the feed tube; they should be finely minced. Set aside.
Heat the olive oil in a nonstick sauté pan. Add the onions and cook until softened;
push to one side and add the chicken. Sauté until lightly browned.
Add the garlic-chile mixture; sauté 1 minute. Add the tomato, potato, raisins
and capers. Season with the cumin, salt and pepper. Remove from heat.
Combine the filling and the corn batter. Place about 1/2 cup of the mixture in
the middle of a corn husk. Wrap the husk around the mixture and tie on both ends
with string. Continue with remaining tamale mixture and corn husks.
Steam the tamales over barely simmering water for 1 hour. Check on the water
level from time to time; add boiling water, if necessary.