Set tortillas aside to partially thaw.In large skillet,heat oil; saute onion and garlic for one minute.Add chicken,chicken broth, chilies,raisins and seasonings.Dissolve cornstarch in water;add gradually to skillet and cook until thick and bubbly.Remove from heat.Heat 0 cm oil in another skillet over medium heat until hot. Separate tortillas and saute,one at a time,a few seconds on each side,until limp.(Do not cook too long or they will become crisp and impossible to roll.)Drain on paper toweling.Fill each tortilla with about 2 heaping tablespoon. chicken mixture across center,keeping filling 3 cm from edges.Roll tortilla around filling.Place two or three flautas,seam side down,in hot oil.Saute,turning on all sides, until crisp,about 30 seconds.Drain on paper toweling;keep warm while frying the rest.Serve with sour cream as a dip. Makes 12.