1 In a small heatproof bowl, soakthe dried mushrooms in thewaterfor 15 minutes or until softened.
Overa small bowl, drain the mushrooms in a sieve lined with cheese cloth or papertoweling; reserve mushrooms and liquid.
2 Meanwhile, in a 12 inch nonstick skillet, heattheoil over moderate heat.
Add the garlic and fresh mush-rooms and saute, stirring occasionally, for 5 minutes or until softened.
Add the tomatoes, soaked mushrooms and their liquid, tarragon, and salt and bring to a boil.
Lower the heat and simmer, uncovered, for 10 minutes or until thickened.
Stir in the tuna and pepperandsimmer for 5 minutes or until hot.
3 Meanwhile, bring a stockpot of unsalted water to a boil.
Add the fettuccine and cook for 6 to 8 minutes or until tender but still firm to the bite.
Drain and transfer to a heated serving bowl.
Add the sauce and toss well to coat.