Melissa Clark's sausage salad (recipe link attached) is a weeknight staple for us. It takes all of 10 minutes and has tons of flavor and texture. This tweaked version uses duck sausage and adds whole grain mustard and an egg on top.
Brown loose sausage in olive oil, breaking it up with a wooden spoon. Add smashed up garlic, cook, then deglaze with vinegar. Remove from heat and stir in a dollop of mustard. Pour the whole mess over radicchio and frisée. Toss. Add more olive oil and vinegar, and season with salt and pepper to taste. Serve with a fried egg on top if you like.