Combine the zucchini, whole tomatoes, onions, and whole mushrooms in a large container.
You can use a skewer to create a "pilot hole" in the vegetables. This may help the marinade to penetrate more as well as make skewering easier later.
In a jar with a tight fitting lid, combine the oil, vinegar, garlic, chili flakes, herbs, and salt. Cover tightly and shake to completely blend.
Pour the dressing over the vegetables. Toss to coat and store covered in the refrigerator for at least 4 hours and as long as overnight.
When you are ready to assemble the kabobs, slice the sausage into 1 inch chunks. Remove the vegetables from the marinade with a slotted spoon. Save the dressing to baste with later.
Skewer the sausage and vegetables in random order. (Don't worry about a pattern unless that's your thing).
Heat the grill to high ( or as high as it will go) and lightly coat with grill spray. Place the skewers on the grill and brush with the reserved dressing.
Continue to grill, turn, and baste until everything is beginning to brown. This will take 15 - 20 minutes depending on the heat of your grill.
Remove the kabobs from the grill and carefully slide the meat and veggies off the skewer.
Heat the olive oil in a large fry pan, swirling to coat the bottom. Add the farro and cook for 5 minutes or so until it begins to brown. Add the garlic and cook another minute or so.
Add the vermouth (or dry white wine) and cook for 2 - 3 minutes. Most of the wine should evaporate.
Add the spinach and about 1 cup of the stock. Allow to simmer, stirring frequently until most of the stock has been absorbed.
Add the red pepper and another cup of stock. Continue the simmering process allowing the stock to be absorbed.
Give the farro a taste at this point. If you like the texture, it's done. If you like it softer, add a little more stock and continue to cook until the texture makes you happy.
Season with salt and pepper to your taste and serve it with the kabobs.