Toast the nuts in a large, dry skillet over low heat, stirring frequently, until golden, about 5 minutes. Remove the nuts.
Cut the bacon into ½-inch pieces and add to the skillet. Cook over medium heat until crisp. Remove the bacon with a slotted spoon and drain on paper towels.
Whisk the oil, mustard, lemon juice, sugar, salt, and pepper in a medium bowl. Tear the frisée into small pieces and place in a serving bowl. Add the bacon, nuts, and goat cheese. Toss the salad with the dressing.