- 1 quart vegetable stock
- 1 cup water
- 1 1/2 teaspoons lobster base
- 4 potatoes, cut into bite-size pieces
- 1 tablespoon butter, or to taste
- 1/2 onion, halved and sliced
- 2 teaspoons dried tarragon
- 2 teaspoons arrowroot powder
- 1 cup half-and-half
- Place vegetable stock, water, and lobster base in a large stockpot; bring to a boil. Stir in potatoes; boil until tender, about 15 minutes. Drain potatoes, reserving stock.
- Melt butter in the stockpot over medium heat. Add onions and tarragon; cook and stir until onions are translucent, about 5 minutes. Add arrowroot; stir until thoroughly combined. Pour reserved stock back into the stockpot. Stir in half-and-half and bring bisque to a boil. Return potatoes to the stockpot; lower heat and simmer until heated through, about 5 minutes.