In a large skillet over medium heat, pour in the olive oil. Once shimmering, add the diced onion and zucchini. Sauté for 4-5 minutes until the onion turns translucent and the zucchini gets lightly browned. Then, set these veggies aside.

Raise the heat to medium-high and add the ground turkey to the skillet. Break it into chunks with a spatula and cook for 7-10 minutes until it's browned and fully cooked through. Drain any excess fat if necessary.

In a small bowl, combine the soy sauce, brown sugar, grated ginger, and sesame oil. Whisk until it's nicely blended, creating a flavorful sauce to coat your skillet ingredients.

Toss in the minced garlic and diced red bell pepper to the browned turkey. Cook for 1-2 minutes, allowing the garlic to become fragrant. Next, return the sautéed zucchini and onion back to the skillet, mixing them in.

Pour the prepared sauce over your skillet mixture. Stir everything together and continue to cook for another 2-3 minutes, stirring occasionally until the sauce thickens slightly.

If using spinach, toss it into the skillet and stir until it wilts down, which should take about 1-2 minutes.

Finally, season your skillet creation with salt and pepper to taste. For the finishing touch, garnish with sliced green onions and a sprinkle of sesame seeds.