In a saucepan, bring the wine, port, black peppercorns, shallot, thyme sprigs and 1 cup of the sugar to a boil, stirring until the sugar dissolves.
Using a moistened pastry brush, wash down any sugar crystals on the side of the pan. Cook over moderate heat, without stirring, until syrupy and reduced to 1 cup, about 35 minutes. Strain and discard the solids. Let the caramel cool slightly.
Meanwhile, in a medium saucepan, toss the strawberries, orange zest, water and the remaining 1/2 cup of sugar and let stand until juicy, about 30 minutes.
Bring the strawberries to a boil and simmer over moderate heat until slightly thickened and jammy, about 15 minutes. Transfer the compote to a bowl and let cool.
In a medium bowl, using an electric mixer, beat the goat cheese, cream, ground pepper and chopped thyme until creamy.
Spoon the mousse into a bowl and serve with the compote, caramel, crostini and walnuts so guests can assemble their own.