Cokk's Illustrated had an interesting article in January on slow-roasting an eye-round that you might find interesting and might work in to the WSM. I've been wanting to try it myself:
IMPROVING CHEAP ROAST BEEF
Adapted from Cook's Illustrated, Jan 2008
The best cut for out roast is the eye-round, which has good flavor and tenderness and a uniform shape that assures even cooking. When choosing between the two classic methods for roasting meat—high and fast or low and slow, we found that low temperature was the best and that it was necessary to keep the meat's internal temperature below 122 degrees for as long a time as possible to allow the meat's enzymes to act as natural tenderizers, breaking down its tough connective tissue (this action stops at 122 degrees). Since most ovens' lowest temperature is 200 degrees, and in order to lengthen this tenderizing period, the meat was roasted at 225 degrees (after searing it to give the meat a crusty exterior) and turned off the oven when the roast reached 115 degrees. Thus, the meat stayed below 122 degrees for 30 minutes longer, allowing the enzymes to continue their work before the temperature reached 130 degrees for medium-rare. Salting the meat 24 hours before roasting made it even more tender and seasoned the roast throughout.
SLOW-ROASTED EYE-ROUND BEEF
We don't recommend cooking this roast past medium. Open the oven door as little as possible and remove the roast from the oven while taking its temperature. If the roast has not reached the desired temperature in the time specified in step 3, heat the oven to 225 degrees for 5 minutes, shut it off, and continue to cook the roast to the desired temperature. For a smaller (2 1/2- to 3 1/2-pound) roast, reduce the amount of kosher salt to 3 teaspoons (1 1/2 teaspoons table salt) and black pepper to 1 1/2 teaspoons. For a 4 1/2- to 6-pound roast, cut in half crosswise before cooking to create 2 smaller roasts. Slice the roast as thinly as possible and serve with Horseradish Cream Sauce (see related recipe), if desired.
Serves 6 to 8
1 boneless eye-round roast (3 1/2 to 4 1/2 pounds) (see note)
4 teaspoons kosher salt or 2 teaspoons table salt
2 teaspoons vegetable oil plus 1 tablespoon
2 teaspoons ground black pepper
1. Salt the complete roast evenly.. Wrap with plastic wrap and place in the refrigerator for 18 to 24 hours.
2. Adjust oven rack to middle position and heat oven to 225 degrees. Pat roast dry with paper towels; rub with 2 teaspoons oil and sprinkle roast with pepper. Heat remaining tablespoon oil in 12-inch skillet over medium-high heat until starting to smoke. Sear roast until browned on all sides, 3 to 4 minutes per side. Transfer to wire rack set in rimmed baking sheet. Roast until meat-probe thermometer or instant-read thermometer inserted into center of roast registers 115 degrees for medium-rare, 1 1/4 to 1 3/4 hours, or 125 degrees for medium, 1 3/4 to 2 1/4 hours.
3. Shut down oven; leave roast in oven, without opening door, until instant-read thermometer inserted into center of roast registers 130 degrees for medium-rare or 140 degrees for medium, 30 to 50 minutes more. Transfer roast to carving board and let rest 15 minutes. Slice meat crosswise as thinly as possible and serve.
STEP BY STEP: The Transformation From Tough to Tender
Along with salting and searing, the key to our eye round's success for a tender, juicy roast is keeping its internal temperature below 122 degrees for as long as possible. Below 122 degrees, the meat's enzymes act as natural tenderizers, breaking down its tough connective tissues.
1. SALT: Salt the roast and allow it to rest for 18 to 24 hours. Salt breaks down proteins to improve texture.
2. SEAR: Sear the meat in a hot pan before roasting. While this won't affect tenderness, it will boost flavor.
3. OVEN ON: Cook the meat in an oven set to 225 degrees and open the door as infrequently as possible.
4. OVEN OFF: When the roast reaches 115 degrees, turn off oven and continue to cook the roast as the oven cools.
HORSERADISH SAUCE
Makes about 1 cup
1/2 cup heavy cream
1/2 cup prepared horseradish
1 teaspoon table salt
1/8 teaspoon ground black pepper
In a medium bowl, whisk cream until thickened but not yet at the soft-peak stage, 1 to 2 minutes. Gently fold in horseradish, salt, and pepper. Transfer to serving bowl and chill at least 30 minutes or up to 1 hour before serving.