Place the cornmeal, mayonnaise, egg, chives, lemon zest, salt, and pepper in a bowl and whisk together until well combined. Add salmon and bell pepper, and mix until well combined.
Shape the mixture into 8 patties. OPTIONAL: Coat the outside of the patties with extra cornmeal/breadcrumbs.
Heat half the oil in a large nonstick skillet over medium-high heat. Cook half the cakes until the bottoms are golden brown, 4 to 5 minutes. Adjust heat to medium if the bottoms start to burn. Flip the cakes and cook until golden brown, an additional 4 to 5 minutes. Repeat with remaining oil and cakes.
Make the lemon crema by mixing together the yogurt and lemon juice. Top the salmon cakes with a sprinkling of chives or other herbs and serve with crema on the side.