Preheat oven to 375 degrees F.
Butter six (3/4-cup) ramekins (3 3/4 by 2 inches). Crumble goat cheese and separate eggs. In a saucepan melt butter over moderately low heat and whisk in flour. Cook roux, whisking, 3 minutes and whisk in milk. Bring mixture to a boil, whisking constantly, and simmer, whisking occasionally, 3 minutes. Remove pan from heat and add yolks, mustard, 1 teaspoon thyme, 2/3 cheese, and salt and pepper, to taste, whisking until cheese is melted. Transfer yolk mixture to a large bowl.
In another large bowl with an electric mixer beat whites with a pinch salt until they just hold stiff peaks. Stir 1/4 whites into yolk mixture to lighten and fold in remaining whites and remaining cheese gently but thoroughly.
Divide souffle mixture among ramekins and arrange in a large baking pan just large enough to hold them. Add enough hot water to baking pan to reach halfway up sides of ramekins. Bake souffles in middle of oven until slightly puffed and golden brown, about 20 minutes, and transfer to a rack. Let souffles stand, uncovered, 30 minutes (souffles will fall slightly).
Lightly butter a baking sheet. Run a thin knife around edges of souffles. Invert each souffle onto palm of your hand and carefully put, right side up, onto baking sheet. Souffles may be made up to this point 2 days ahead and chilled, covered.
Increase temperature to 425 degrees F.
In a small saucepan bring cream with remaining teaspoon thyme, salt and pepper, to taste, to a boil. Remove pan from heat and keep cream warm, covered. Bake souffles in middle of oven until slightly puffed and heated through, about 5 minutes.
Transfer souffles to plates. Spoon 2 tablespoons cream over each souffle and arrange salad decoratively alongside.