First, make the herb-feta relish: Mix the 1/4 cup minced parsley, the 1/3 cup minced basil, the 1 clove minced garlic, the 1 tablespoon lemon juice, the 1/2 teaspoon kosher salt, the 1/4 teaspoon black pepper, and the 1/4 teaspoon red chile flakes in a small bowl. Stir in the olive oil then gently stir in the feta trying not to break it up too much. You can make this up to 3 days in advance and keep covered in the refrigerator or let it sit out while you prepare the polenta and veggies.
For the polenta: Bring 4 cups of water to a boil in a large saucepan with a lid over high heat. Add 1 teaspoon of kosher salt, then slowly whisk in the 1 cup of polenta. Reduce heat to low and cook, stirring frequently with a wooden spoon until polenta is creamy, thick, and tender, about 20 minutes. Add the 6 ounces shredded fontina cheese and stir until melted and combined. Cover and remove from heat.
Meanwhile, heat oil in a large frying pan with a lid over medium-high heat. Add onion and potatoes and season with 1 teaspoon kosher salt and 1/2 teaspoon pepper. Cook, stirring occasionally until starting to brown.
Add the 3 cloves sliced garlic, the sliced bell pepper, and chopped zucchini and season again with 1/2 teaspoon salt and 1/4 teaspoon pepper. Once garlic starts to brown add 1/2 cup wine and scrape up any browned bits from the bottom of the pan.
Add the 3 thyme sprigs and 1/2 cup broth and cover. Reduce heat to medium-low and cook until potatoes are fork tender, about 10 minutes. Taste and season again if necessary.
Check to see if polenta is still warm. If not, add 1/4 or so more water and return to medium-low heat. Stir until polenta is smooth and warmed through.
Spoon polenta into shallow bowls, top with veggies, drizzle with herb relish and sprinkle with a few more basil leaves if you'd like.