This is my take on a vegetarian curry. You can make it as mild or spicy as you like by just adjusting the amount of green curry paste. Remember one of the keys to a great curry is proper seasoning so make sure you taste and adjust as needed.
In a 12" skillet heat olive oil over medium heat. Add shallots and garlic and saute until shallots are translucent. Be careful to NOT burn the garlic.
Add 1/2 the can of coconut milk and bring to a boil. Boil for 3 minutes.
Add curry paste to the coconut milk in the skillet. For milder sauce use 2 teaspoons of the paste. For hotter use 1 tbsp or more.
Once the paste incorporates into the coconut milk add the remaining 1/2 can of coconut milk and the broth. Season with salt and pepper. Stir well.
Add the cauliflower to the skillet. Bring the mixture to a boil and then lower the heat and simmer for 10 minutes.
Add the squash and the zucchini to the pan and return to a boil. Lower the heat again to a simmer and cook until all the vegetables are tender for about 15-20 minutes longer.
Be sure to stir the mixture periodically. If you find that the vegetables are not cooking fast enough, cover the pan in the last 10 minutes.