How to Make It
Heat a large cast-iron pan or grill pan over high. Add tomato slices to pan; cook 6 minutes on each side or until well charred. Place tomatoes in a blender. Add parsley, capers, 1/4 cup olive oil, rosemary, juice, vinegar, 2 garlic cloves, 1/4 teaspoon salt, and 1/4 teaspoon pepper; blend until smooth.
Heat a large nonstick skillet over medium-high. Add 1 tablespoon oil to pan. Add bell peppers, shallot, and sliced garlic cloves; sauté 4 minutes or until tender. Add chard; sauté 2 minutes or until just wilted. Remove from heat; stir in chopped basil.
Sprinkle trout inside and out evenly with remaining 1/4 teaspoon salt and remaining 1/2 teaspoon pepper. Place about 1/2 cup chard mixture in each butterflied trout, and fold halves back together.
Preheat oven to 400°F. Spread charred tomato mixture in bottom of a 9- x 13-inch glass or ceramic baking dish. Sprinkle olives over tomato mixture; spread thyme sprigs over mixture. Heat remaining 1 tablespoon oil in large nonstick skillet over medium-high. Add 2 stuffed trout to pan; cook 2 minutes or until skin is golden brown. Turn trout over; cook 2 minutes. Place browned trout in prepared baking dish. Repeat procedure with remaining 2 trout. Place baking dish in oven; bake at 400°F for 12 minutes or until trout is just cooked through.