Combine the tomatoes, roasted red pepper, shallot, and garlic in a high-speed blender; process until perfectly uniform and smooth.

In a heavy-bottomed brazier or wide skillet, heat the oil over medium-high heat until shimmering.

Add the raw rice to the oil and sauté, stirring constantly, until the grains turn a pale, toasted gold color and become translucent at the edges.

Pour the vegetable puree into the skillet, stirring for one minute to cook off the raw scent, then add the stock, salt, paprika, and the serrano pepper.

Bring the mixture to a gentle simmer, cover with a tight-fitting lid, and lower the heat to the absolute minimum setting. Cook for 20 minutes, then remove from heat and let rest, covered, for another 10 minutes.

Remove the serrano pepper, fluff the rice gently with a fork, and fold in the fresh parsley before serving.