One 7-ounce block feta cheese, drained and crumbled
1/2 cup chopped fresh basil (about 12 large leaves)
Set the oven to 375 degrees Fahrenheit.
Remove the peppers' very tops. The peppers should have their ribs and seeds removed and thrown away.
In a colander placed over a medium bowl, drain the tomatoes. To capture any remaining liquids, place the tomatoes over a dish and reserve the juice. While making the filling, combine the couscous, oregano, tomato juice, 1 teaspoon salt, and 1/2 teaspoon black pepper. Set aside.
Over medium-high heat, warm 1 tablespoon of the olive oil in a big skillet. Add the onion, zucchini, the remaining garlic, 1/2 teaspoon salt, and simmer, turning often, for approximately 3 minutes, or until the veggies are softened and just starting to brown. Turn the heat up to high, pour in the couscous mixture, and boil quickly, stirring regularly, for about 5 minutes, or until the couscous is just tender and the liquid is starting to thicken. Spinach should be added and cooked for about 30 seconds, stirring occasionally and adjusting the heat as needed, until the leaves are bright green and just starting to wilt. Place the filling aside to slightly cool.
In a Dutch oven, combine the remaining garlic and olive oil with any chile flakes you're using to make the sauce, and stir to blend. Place the pot over medium-high heat, and cook, stirring periodically at first, then more often as the oil begins to crackle to keep the garlic from burning, for 2 to 3 minutes, or until the garlic starts to adhere to the edge of the spoon and is just starting to turn a very pale straw color. Add 1 cup water, 1 cup of the reserved, drained tomatoes along with any accumulated juices, 1/2 teaspoon of salt, and 1/2 teaspoon of black pepper. Stir often and boil for about 3 minutes, or until the mixture just starts to come together and thicken. Get rid of the heat.
The couscous filling should be folded with the feta and basil. About 3/4 cup of the filling should be placed inside a pepper; shake the pepper to level the filling rather than pack it down. Place the stuffed pepper within the sauce in the pot, and then do the same with the remaining peppers, balancing them against the pot's sides for stability while baking.
For 45 to 60 minutes, bake the pot with the cover on until the sauce is bubbling and the peppers are soft but not mushy. The peppers must be tender but not soft after 45 minutes to avoid being overdone and becoming mushy. Before serving, allow it rest for at least 15 minutes. Serve with a heaping scoop of tomato sauce whether it is hot, heated, or at room temperature.