Cook and stir prosciutto in 1 tsp. of the oil in large skillet on medium heat until crispy.
Remove prosciutto from skillet with slotted spoon; set aside.
Add mushrooms, onions, garlic, rice and remaining 3 tsp. oil to skillet; stir until rice is evenly coated with oil. Cook until onions are tender, stirring occasionally.
Add 1 cup of the broth, cooking and stirring constantly until broth is absorbed. Repeat with remaining broth, adding broth 1 cup at a time and cooking until rice is tender but firm.
Stir in peas, Parmesan cheese and blue cheese; cook until cheeses are completely melted, stirring frequently. Spoon onto serving platter. Top with the prosciutto; sprinkle with parsley.