Finely chop one yellow pepper, saute in 1 tbsp butter until tender. Set aside.
Place pin nuts, lemon juice, salt, pepper and remaining butter in a blender. Cover and process until blended. Add cooked pepper and blend. Set butter aside.
Place beans in a saucepan and cover with water. Cut remaining pepper into thin strips, add to beans. Bring to a boil. Cover and cook for 5-7 minutes, or until crisp, drain. Place in bowl and toss with butter.