Begin by washing and slicing the onion, carrots, sweet potato, kale, and zucchini.
Heat the olive oil in a large skillet over medium heat. Add the onion, carrot, and sweet potato. Cook, stirring frequently, for about 8 minutes to give the heartier veggies a head-start to get tender.
After 8 minutes, add the kale and zucchini. Cook for another 4-5 minutes.
Once tender, add the thyme, Cajun seasoning, salt, and pepper. Then, add 2 cups of the chicken broth. Bring to a simmer.
Mix the remaining 2 tablespoons of broth with the cornstarch. Mix with a fork to remove any lumps.
Pour the cornstarch slurry into the simmering broth and veggies. Cook for 2-4 minutes until the sauce starts to thicken.
Pour the veggie stew into a heavy-bottomed baking dish. Set aside and make the topping.
Preheat the oven to 350 degrees F.
Combine the flour, oats, melted butter, salt, thyme, and Parmesan. Mix until you have a crumbly mixture that holds together when squeezed in your hand.
Place the topping on top of the veggies in large mounds evenly over the top. Place a baking tray under the baking dish in case of any spillage in the oven.
Bake the crisp for 25-30 minutes until the topping is golden brown and the veggies are bubbly.
Allow to cool 5-10 minutes before serving.