Cook onions in butter in large skillet over medium-high heat until soft. Add rice and saffron; stir 2 to 3 minutes. Add wine; stir until absorbed.
Stir in 1 cup broth; cook, uncovered, stirring frequently, until broth is absorbed. Continue stirring and adding remaining 1 cup broth and 3 cups water, allowing each to be absorbed before adding another, until rice is tender and mixture has a creamy consistency. It will take approximately 25 to 30 minutes.
Stir in peas, crawfish, Parmesan cheese, salt, cream, lemon juice, and hot pepper sauce. Cook until risotto is thoroughly heated, about 2 minutes.
If crawfish is unavailable, substitute deveined medium shrimp.