If you have vegetable stock on hand (see a recipe for D.I.Y. stock here), it’s a breeze to make soup with almost any vegetable you have lying around. Here is a master recipe. Experiment at will!
1 medium onion, diced
2 cups *raw or *roasted vegetables, in your preferred combination
1 quart vegetable stock
1 tbsp. olive oil
Salt and pepper to taste
Heat olive oil in a medium-sized soup pan. Add onion and sauté over medium heat until translucent. Add vegetables and stock and cook until vegetables are tender. Cover and remove from heat, let cool for ½ hour. Puree in blender until smooth, return to soup pan, season to taste and reheat until warm.
*While some vegetable soups (we’re looking at you, broccoli and spinach) are better with fresh vegetables, roasting vegetables, particularly root vegetables and squashes, adds a nice richness and sweetness to your soup. For the best of both worlds, use a combo of roasted and fresh veggies, such as half roasted carrot and fennel with half raw carrot and fennel (one of my favorite combinations).
Other favorite vegetables to roast for soup include:
cauliflower, garlic, fennel, and parsnips
To make a vegetable bisque (particularly good for roasted root vegetables), stir 2 tsp sherry and ¼ cup heavy cream into the pureed soup.