Bake pecans in a shallow pan at 350°, stirring occasionally, 5 to 10 minutes or until toasted. Set aside.
Cut each pear into thin slices. Combine pear slices, water, and lemon juice in a large bowl.
Beat butter and blue cheese at medium speed with a mixer until mixture is smooth.
Drain pear slices on paper towels. Spread butter mixture on bottom half of pear slices; coat with pecans, and place on a serving plate. Cover and chill 30 minutes.