Place the arugula, garlic, water, and oil in a blender; blend until smooth.
In a large mixing bowl, combine the flour, gluten, yeast, sugar, and salt.
Add the wet ingredients to the dry.
Using a stand mixer fitted with a dough hook, mix for about 6 minutes, until a dough forms.
Add more flour, 1 tablespoon at a time while mixing, if needed.
Alternatively, if you don’t have a stand mixer, transfer the dough to a lightly floured surface and knead for 8 to 10 minutes, adding 1 tablespoon flour at a time if needed, until the dough is smooth and pliable.
Lightly oil a large bowl and place the dough in it.
Turn to coat.
Cover tightly with plastic wrap and let rise for 60 to 90 minutes, until doubled.
Lightly coat an 8 x 4-inch loaf pan with spray.
Gently punch down the dough and press it down into the pan.
Loosely cover with plastic wrap and let rise until the dough reaches 1 inch over the top of the pan, between 30 and 60 minutes.
Preheat the oven to 375°F.
Carefully remove the plastic wrap and bake for 30 minutes, or until golden brown and the bottom of the bread sounds hollow when tapped.
Remove from the pan, transfer to a wire rack, and let cool before slicing.