Preheat and Prep: Preheat your oven to 450°F (230°C). Gently warm the vegetable stock in a small saucepan over low heat.
In a medium bowl, toss the tomato wedges with 1 tablespoon (15 ml / 0.5 fl oz) of olive oil and a sprinkle of salt and pepper.
Sauté the Base: Place a 10- or 12-inch ovenproof skillet over medium-high heat and add the remaining 3 tablespoons (45 ml / 1.5 fl oz) of olive oil.
Add the minced onion and garlic, season with salt and pepper, and cook, stirring occasionally, until softened, about 3-5 minutes.
Build the Flavor: Stir in the tomato paste, saffron (if using), and smoked paprika.
Cook for one minute more until fragrant.
Add the rice to the skillet and stir for 1-2 minutes until the grains are well-coated and look shiny.
Combine and Assemble: Carefully pour the warm stock into the skillet and stir everything together just once to combine.
Arrange the seasoned tomato wedges on top of the rice, drizzling any accumulated juices from the bowl over them.
Bake to Perfection: Transfer the skillet to the preheated oven.
Bake, undisturbed, for 15 minutes.
Check to see if the rice is tender and the liquid has been absorbed. If not, bake for another 5 minutes. If it looks dry but isn't done, add a splash more stock or water.
Let It Rest: Once the rice is cooked, turn off the oven and let the paella rest inside for 5 to 15 minutes. This step is crucial for the flavors to meld and the texture to set.
Garnish and Serve: Remove the pan from the oven and garnish generously with minced parsley. For an extra crispy bottom (socarrat), place the skillet over high heat on the stovetop for a minute or two until you hear a slight crackling sound.
Serve immediately.
Don't be afraid to experiment! This recipe is fantastic with 1 lb (450g) of cubed eggplant, whole mushroom caps, or even chopped spinach instead of tomatoes.