Cut the top off the head of garlic (just enough to expose the cloves a bit). Place in the center of a square of heavy duty foil. Drizzle with a little olive oil and wrap sealing completely but leaving a little breathing room. Place in a 350 degree oven and bake for 40 minutes or until the kitchen smells wonderful and the garlic feels soft. Unwrap and allow to cool.
Toast the pine nuts on top of the stove. Place them in a dry non-stick pan and toast over low heat shaking frequently to prevent burning. This should take 6 or 7 minutes.
Place the basil and parsley leaves in the bowl of a processor. Squeeze the cooled garlic into the bowl. Add the pine nuts. Pulse to coarsely chop the ingredients.
Add the grated cheese and pulse to combine.
With the motor of the processor running, stream the olive oil into the feed tube. Stop as soon as the mixture is the texture that you like. (Do not process until smooth).
Scrape the pesto into a bowl. Check for seasoning Add some ground pepper and a pinch of salt if you want.
It is now ready to use. It can be frozen in 1/4 cup (or whatever amount you like) packages. It will keep in the refrigerator for a week. Pour a thin layer of olive oil on the pesto before you put it in the refrigerator to help preserve color and flavor.
To make the salsa: Combine the herbs, capers, garlic, lemon zest and juice in the bowl of a processor. Process until coarsely chopped, scraping the bowl as necessary.
Add the olive oil and process until finely chopped, scraping bowl as necessary. If mixture is too thick add water a little at a time until the consistency is as you like it. Pour the salsa into a container cover and refrigerate until ready to use.
Grill or broil the sausages. Allow to cool enough to slice thinly. Combine the sausage slices and the marinara sauce in a saucepan. Simmer for 5-7 minutes.
While the sausage simmers, saute the the onions and peppers in the olive oil. They should be lightly browned but still crunchy.
Assemble the Tacos: Divide the sausage between the tortillas. Top the sausage with the peppers and onions. Add the tomato slices. Drizzle with the Salsa Verde and sprinkle with the cheese.