Prep the Veggies: Wash all of your produce thoroughly. Cut and slice the mushrooms, broccoli, zucchini, yellow squash, bell peppers, and red onion according to the ingredient list guidelines. Leave the cherry tomatoes whole.
Heat the Pan: Place a large, heavy skillet (preferably a well-seasoned cast-iron skillet) over medium-high heat. Pour in 2 tablespoons of the extra virgin olive oil and let it heat for 60 seconds until it shimmers.
Sauté Aromatics: Lower the heat slightly to medium. Add the red onion wedges to the pan and sauté for 3 minutes until they begin to soften. Toss in the minced garlic and cook for 1 additional minute, stirring constantly so it doesn't burn.
Sear the Firm Veggies: Turn the heat back up to medium-high. Add the mushrooms, broccoli florets, and red and yellow bell pepper chunks into the skillet. Sauté for about 4 minutes, tossing frequently to get a light sear on the edges.
Add the Squash: Add the zucchini and yellow squash half-moons to the pan. Cook for another 3 to 4 minutes. The vegetables should begin to develop beautiful, charred, caramelized edges but still maintain a firm, tender-crisp bite.
Blister the Tomatoes: Stir in the whole cherry tomatoes, chopped fresh herbs, sea salt, and black pepper. Cook for 2 to 3 minutes, stirring gently, until the tomato skins start to wrinkle, soften, and slightly burst.
Finish and Serve: Remove the skillet from the heat source. Drizzle the final 1 tablespoon of extra virgin olive oil and the fresh lemon juice across the top. Toss gently one last time. Serve hot directly from the skillet or transfer to a platter. (If using optional toppings like feta or olives, sprinkle them on now!)