If your roast is the rolled-up type, remove mesh or ties from surface and unroll the roast. Arrange garlic cloves evenly on top, then sprinkle freshly ground salt and pepper over the top. Roll the roast up (but don't put any mesh or ties back on).
Start heating the canola or olive oil in a medium nonstick frying pan over medium-high heat. When hot, add the rolled-up roast to the pan and let the bottom brown for a couple of minutes. Flip and brown the other side a couple minutes more. Carefully place browned roast in slow cooker so that it remains rolled up.
Pour onion soup concentrate and wine over the top. Cover and cook on LOW for about 4 hours.