Preheat your oven to 400°F (200°C).

On a baking sheet, arrange the sliced heirloom tomatoes and cherry tomatoes.

Drizzle with olive oil and balsamic vinegar, then sprinkle with minced garlic, fresh thyme, crushed red pepper flakes, salt, and pepper.

Roast in the oven for 20-25 minutes, until the tomatoes are soft and slightly caramelized.

Remove from the oven, discard the thyme sprigs, and stir in the fresh chopped basil. Set aside.

Using a vegetable peeler or mandoline, slice the zucchini into thin, long strips.

Lightly sprinkle the zucchini slices with salt and let them sit for about 10 minutes to remove excess moisture. Pat dry with paper towels.

In a medium bowl, mix together the ricotta cheese, crumbled feta, grated parmesan, and chopped fresh basil.

Lay out two zucchini strips horizontally, slightly overlapping, and then place two more strips on top vertically to create a cross shape.

Place about 1 tablespoon of the 3-cheese filling in the center of the zucchini cross.

Fold the ends of the zucchini strips over the filling to create a small "ravioli" bundle.

Place the zucchini ravioli in a baking dish and pour the roasted tomato basil sauce around the bundles.

Place in the preheated oven and cook for 15 to 20 minutes, or until the zucchini becomes tender and the cheese has melted and turned a light golden color.

Serve the zucchini ravioli with the roasted tomato basil sauce, garnished with extra fresh basil if desired.