In large bowl, dissolve yeast and sugar in water; let stand for 5 minutes. Add oil and salt. Stir in flour, a cup at a time, until a soft dough is formed.
Turn onto floured surface; knead until smooth and elastic, about 2-3 minutes. Place in a greased bowl, turning once to grease the top. Cover and let rise in a warm place until doubled, about 45 minutes. Meanwhile, cook beef and onion over medium heat until no longer pink; drain.
Punch down dough; divide in half. Press each into a greased 12-in. pizza pan. Combine the tomato sauce, oregano and basil; spread over each crust. Top with beef mixture, green pepper and cheese.
Bake at 400° for 25-30 minutes or until crust is lightly browned.