Add 4 tablespoons unsalted butter, oregano, thyme, and half the garlic powder to a small bowl and stir to combine. Setaside.
Add one tablespoon olive oil and the remaining butter to a large nonstick skillet set over medium-high heat. Pat the salmon fillets with paper towels and add to the hot skillet skin side down. Sprinkle with the remaining garlic powder and season with salt and black pepper, as desired.
Cook until the salmon skin is nicely browned and crispy, approximately 4-5 minutes. Carefully turn the fillets and cook on the remaining side for another 3-4 minutes, or until the salmon is golden brown and cooked through.
Remove from heat and transfer the salmon to a platter. Add remaining olive oil to the skillet and set over medium heat. Add garlic, zucchini, yellow squash, and tomatoes. Season with salt and black pepper, to taste, and stir to combine. Cook, stirring occasionally until the vegetables are tender and nicely browned, approximately 4-5 minutes.
Return the salmon to the skillet and top each fillet with some of the herb butter and a squeeze of fresh lemon juice. Garnish with fresh chopped parsley and serve immediately. Enjoy!