In a large fry pan add enough olive oil to cover the bottom and heat until barely shimmering. Add chicken and lightly brown on both sides, remove from pan and set aside. Add more oil and sauté the onions and red pepper until softened, then add the garlic, thyme, and paprika and sauté for another minute or two. Add broth and chicken back into the pan and bring to a boil. Reduce heat and simmer for 20 minutes or so, until chicken is cooked through. Remove chicken again. Whisk the mustard and sour cream into the pan and heat until the sauce is somewhat thickened. Add the chicken back in, heat through, and serve. I like it with roasted potatoes, a big salad, and some crusty bread. Perhaps a nice pinot grigio.