Prep the seafood and mise en place: Rinse mussels and clams under cold water, discard any that remain open when tapped. Peel and devein the shrimp if needed, keeping tails on if you prefer presentation. Pat all seafood dry. Put the saffron threads in a small bowl and pour 2 tablespoons hot stock over them to bloom while you cook — saffron releases its aroma and color when steeped in warm liquid.

Heat a wide paella pan or large skillet over medium heat and add 2 tablespoons of olive oil. Add the diced onion and a pinch of salt and sweat until translucent (about 6–8 minutes). Sweating — cooking gently without browning — softens the onion and builds a sweet base without burning the sugars, which would make the rice bitter.

Add the minced garlic and smoked paprika; cook for 30–45 seconds until fragrant. Toasting the paprika briefly in oil blooms its smoky flavor — do not let it burn or it becomes bitter.

Add the rice (300 g) and stir to coat each grain in the oil and aromatics for 1–2 minutes. Coating the rice in oil 'toasts' the surface slightly and helps the grains stay separate and absorb stock evenly.

Pour in the hot fish stock (720 ml) and the saffron with its soaking liquid; stir once to distribute. Increase heat to medium-high until the stock comes to a gentle simmer, then reduce to maintain an even, gentle simmer. Do not stir from this point forward except to distribute ingredients — paella develops socarrat (a prized caramelized bottom crust) when rice is left undisturbed.

Adjust seasoning with a teaspoon of salt (taste the stock first — if it’s salty, use less) and a crack of black pepper. Let the rice simmer uncovered for about 12 minutes, rotating the pan occasionally to ensure even cooking. You’re looking for rice that is nearly cooked through but still with a slight bite.

Nestle the clams and mussels (hinges down so they close) and the shrimp into the rice surface. Scatter the thawed peas across the top. Pushing the shellfish into the rice lets them steam finish in the rice’s heat and cook evenly — opening shells indicate they’re done.

Continue to cook for another 6–8 minutes at a gentle simmer until the shellfish have opened and the shrimp are opaque and firm. If after 15–18 minutes total the rice still seems too firm but liquid is low, add small splashes (30–60 ml) of hot stock or water — keeping liquid hot prevents shocking the rice and ensures even cooking.

If you want a socarrat (crisp bottom), increase the heat to medium-high for 1–2 minutes at the very end — you should hear faint popping and smell caramelization. Watch closely: this can go from perfect to burnt in 30–60 seconds. Remove from heat when you’re happy with the bottom crust.

Cover the pan with a clean kitchen towel or lid and let the paella rest for 5 minutes. Resting allows steam to redistribute, finishes any remaining cooking gently, and firms the grains slightly for better texture.

Garnish with chopped parsley and lemon wedges. Serve straight from the pan, encouraging guests to squeeze lemon over their portion — the acid brightens the rich, briny flavors and lifts the saffron-scented rice.