Cut the cod into 1-inch chunks and place it in a bowl; add kosher or sea salt, plus freshly cracked peppercorns. Set aside.
Place a large skillet over medium-high heat and add olive oil. When the oil is hot, add Thai red curry paste and tomato paste, and stir for about one minute.
Add the fish sauce, add the onions, and cook, stirring constantly, for two to three minutes.
Add the garlic and continue to stir until the garlic is fragrant, for one minute.
Next, add the fish stock, canned crushed tomatoes, cherry tomatoes, unsweetened coconut milk, and quartered gold potatoes.
Stir in the smoked paprika, red pepper flakes, kosher or sea salt, and freshly cracked black peppercorns.
Reduce the heat to medium-low and cover the skillet with a lid.
Simmer until the potatoes are tender and easily pierced with a fork.
Add the fish, then cover with the lid and cook until the cod is opaque and cooked through in four to five minutes.
Serve