Preparation:
In large sauce pot, cook pasta in salted water according to package directions.
Meanwhile, in small saucepan, heat milk until hot; remove from heat, set aside. Reserve 1/2 cup of the avocado for later use. When pasta is almost cooked, in blender, combine remaining avocado, the peas, cheese and lemon juice; gradually add hot milk; blend until smooth.
Drain pasta; return to sauce pot. Stir in cheese sauce; add remaining 1/2 cup diced avocado; toss gently.