Combine dried mushrooms and boiling water in small bowl to soften.
Prepare pasta according to package directions.
Meanwhile, heat 2 teaspoons oil in large nonstick skillet over medium-high heat. Add chicken to skillet; sauté until golden brown, 3 to 4 minutes. Remove to clean bowl.
Add remaining oil and quartered mushrooms to skillet. Reduce heat to medium; cook until mushrooms release their juices and are lightly golden, about 3 minutes. Remove to bowl with chicken.
Whisk together milk, flour, salt, rosemary and pepper in small bowl until well blended and smooth. Add to skillet. Bring to boiling. Add chicken and mushrooms. Cook, stirring occasionally, until thickened and bubbly, about 3 minutes.
Meanwhile, strain dried mushrooms through paper-towel-lined sieve placed over bowl; reserve liquid. Rinse mushrooms; drain and coarsely chop. Stir into skillet along with strained mushroom liquid, roasted peppers and lemon juice.
Drain pasta; toss with chicken mixture and rosemary.