Begin by preparing the Hilling. Blend the olive oil, basil, garlic, and sea salt well in a basic blender.
After a rich emulsion forms, add in the nuts of choice and blend well until a thick paste forms.
Chop the sun-dried tomatoes evenly and fold into mixture.
Slice the red bell pepper lengthwise and remove stem and seeds. Dice down to 1/8 inch pieces and add to Hilling mixture.
In a medium-size mixing bowl, toss the mushrooms (after de-stemming and wiping clean with a damp cloth) with a little olive oil until lightly coated.
On a baking tray, arrange mushrooms concave side up so that they are barely touching one another.
Fill mushroom caps evenly with Hilling. Bake at 200 degrees for 20 minutes and then check. Enjoy topped with additional nuts, marinara, or dried herbs.