Combine peas, 2 tablespoons stock, cheese, mint, 1/2 teaspoon salt, and garlic in a food processor; process until smooth.
Sprinkle fish with remaining 1/2 teaspoon salt and pepper. Heat a non-stick skillet over medium-high heat. Add 1-1/2 teaspoons oil and 2 filets; cook 3 minutes on each side or until done. Remove from pan. Repeat procedure with remaining oil and 2 filets.
Thinly slice shallot and add to pan; cook 1 minute. Add wine and juice; bring to a boil. Cook 3 minutes. Add remaining 10 tablespoons stock. Simmer 3 minutes, then stir in butter.
Divide pea mixture and filets among 4 serving plates; drizzle shallot mixture evenly over fish.f