Grapeseed Oil Focaccia with Grapes and Walnuts

Name: Grapeseed Oil Focaccia with Grapes and Walnuts
Ingredients: 1 1/3 cups warm water; 3 teaspoons active dry yeast; 1 1/2 teaspoons sugar; 1/2 cup Salute Sante! Chardonnay grapeseed oil, plus extra for brushing; 3 cups all-purpose flour (may substitute up to 1/4 cup with Salute Sante! grapeseed flour); 3/4 teaspoon kosher salt; 1 1/2 cups black or red small seedless grapes; 1/4 cup plain grapeseed oil; 1/2 cup walnuts, coarsely chopped; 1/2 tablespoon coarse flake salt (such as Maldon)