Place the green beans and red onion in a large bowl. In a small bowl, whisk together the garlic, mint, lemon zest and juice, and mustard. While whisking, slowly add the olive oil and whisk until thick and emulsified. Whisk in the sour cream and Tabasco. Season to taste with salt and pepper. Pour the dressing over the beans and toss well. Refrigerate at least 30 minutes or up to 24 hours before serving.
Reprinted with permission from Caprial Cooks for Friends by Caprial Pence. Copyright 2000. Ten Speed Press, Berkeley, CA.