Twenty-three miles south of Anchorage on the Seward Highway, the first glimpse of Froth & Forage’s turquoise roof comes two mountainside highway curves ahead of the restaurant’s gravel parking. Though the weathered wood building looks like the barbecue shack it was in a past life, it is now home to a 22-seat restaurant headed up by a chef who wants to prove that a restaurant in south-central Alaska can thrive using local ingredients or, at least, other small local purveyors, instead of goods delivered from, as Alaskans call it, Outside.