COOK pasta as directed on package. Stir in tomatoes and escarole. Drain; keep warm.
MIX 1/4 cup cashews and white sauce mix in same pan; gradually stir in milk. Cook on medium heat until thickened.
RETURN pasta and vegetables to pan. Toss with sauce and lemon juice. Spoon onto serving platter; sprinkle with remaining cashews. Serve immediately.