Cook penne until al dente and drain. Rinse. If you will be holding the penne longer than 10 to 15 minutes, toss it with a bit of olive oil to prevent sticking. In a large saute pan, heat olive oil until hot. Add garlic and shallots and cook until you can smell the aroma, 1 or 2 minutes. Add tomatoes and toss. Add stock and cook over medium heat until about 1/3 cup of liquid remains, 5 to 7 minutes. Add hot smoked salmon and penne and toss to coat and rewarm the penne. Add lemon zest and juice and cook for about 1 minute. Add sour cream and chives and cook just until they are warmed through. Season with salt and pepper to taste. Serve hot. Serves four. Per serving: 593 Calories (kcal); 45g Total Fat; (66% calories from fat); 9g Protein; 40g Carbohydrate; 67mg Cholesterol; 337mg Sodium Food Exchanges: 0 Grain(Starch); 0 Lean Meat; 4 1/2 Vegetable; 1/2 Fruit; 8 Fat; 0 Other Carbohydrates Converted by MM_Buster v2.0n.