Line two 8-by-4-inch loaf pans with plastic wrap, leaving a 4-inch overhang on all sides. Line the bottom and sides of each pan with one-fourth of the smoked salmon slices, slightly overlapping them. Add 3/4 cup of poblano cream and spread in an even layer. Season the salmon fillets with salt, pepper and the remaining lemon juice; center a fillet on the cream in each pan. Spread half the remaining poblano cream over each salmon fillet and cover with half the remaining smoked salmon. Fold the overhanging plastic up and over the top of the terrine and refrigerate until firm, at least 6 hours and up to 12 hours.