To prepare a Spanish vegetable stew with squash stews recipe, first you will need to gather your ingredients. First, you'll need the following ingredients: Vegetables: You can use any vegetable you like, but I like to use carrots, sweet potatoes, squash, and sweet peppers. If you don't have any of these ingredients, then you can skip this step. Next, cook the vegetables over medium-high heat until they're tender, about 20 minutes. Then, add the squash and cook until it's tender and wilted, 10 to 15 minutes more.