While some meat-focused recipes may suffer if you remove their beefy components, paella — often made with chorizo, chicken and shellfish — isn’t one of them. This classically Spanish meal is rice based, and so long as you keep the bold flavors of spices like paprika and saffron, it will maintain its tried-and-true flavor when you swap out the meat for nearly any and all of the vegetables in your refrigerator.
Preheat the oven to 450 degrees. Core the tomatoes, cut into wedges and place in a medium bowl; season with salt, drizzle with a bit of olive oil and toss. Set aside.
Heat 1/4 cup olive oil in a 12-inch ovenproof skillet or a paella pan over medium-high heat. Add the onion, garlic, paprika, cayenne and saffron and season with salt. Cook, stirring occasionally, until the onion softens, about 5 minutes.
Add the fennel wedges and cook until lightly browned on one side, about 5 minutes. Flip the fennel and add the baby artichokes and eggplant to the skillet; cook until slightly tender, about 4 more minutes. Add the mushrooms and cook for 1 to 2 minutes. Pour in the wine and simmer until reduced by about one-third. Stir in the rice and 1 3/4 teaspoons salt; add just enough water to cover the rice completely, 2 1/2 to 3 cups. Increase the heat to high and boil for 2 to 3 minutes. Scatter the green beans and 2 tablespoons capers over the rice. Remove the pan from the heat and arrange the tomatoes on top; drizzle with any tomato juices.
Transfer the paella to the oven and bake, undisturbed, for 20 minutes. Scatter the remaining 2 tablespoons capers and the peppers over the paella. Turn off the oven but leave the paella inside to continue cooking until the rice is tender, 15 to 20 more minutes. Garnish with parsley, if desired.