In a large pot of boiling salted water, cook the brussels sprouts until crisp-tender, about 5 minutes. Drain and pat dry. Slice the sprouts in 2-3 pieces.
In a large, deep skillet, heat 2 tablespoons of the oil. Add the shallots and cook over moderately low heat, stirring, until lightly browned, 10 minutes; scrape into a bowl.
Add the remaining 2 Tbsp. of oil to the skillet. Add the brussels sprouts, cut side down, and the bacon. Season with salt and cook over high heat, stirring occasionally, until the sprouts are browned and tender, 10 minutes. Season with salt, transfer to a bowl and serve.