She’s equal parts Mildred Pierce, Julia Child, and Danai Gurira. She’s in her muu-muu with house slippers. Her hair is wrapped, and she’s cooking. She’s Greta Oblesby, playing “Mama,” in a marvelous, alive production of Zora Howard’s Pulitzer Prize-shortlisted play, STEW. Newly produced by Ebony Repertory Theater and directed by Jade King Carroll, it’s now ...