Heat the olive oil in a large nonstick skillet over medium-high heat. Add the diced onion, and sauté 5 minutes. Add diced potato, black pepper, and minced garlic, and cook 15 minutes, stirring frequently. Add diced beets, and sauté 5 minutes. Add smoked turkey breast, and sauté 1 minute. Combine the water, sour cream, mustard, and thyme, and stir into turkey mixture. Remove from heat; cover and let stand 3 minutes.