Prepare Fresno chile vinaigrette
Add the diced Fresno chili and onion to a small mixing bowl with the lemon juice, olive oil, agave, and 1 tsp. salt. Whisk to combine.
Prepare pan-seared fish
Lay the cod fillets out on a cutting board, cut into 4 equal portions and pat dry with paper towels. Season both sides with salt and pepper.
In a preheated pan on high heat, add oil and swirl to coat the bottom of the pan. When the oil starts to smoke, carefully add the fish portions to the pan. Cook 3-4 minutes or until golden brown on first side, then flip and continue cooking about 2-4 minutes more, depending on the thickness of the fillets. When the fish is just about cooked through, smash a garlic clove and add it to the pan with the butter and the thyme sprigs. As the butter melts, tip the pan so the garlic and thyme infuses the butter, and baste the fish for 15-20 seconds.
Transfer the fish to a warm plate to rest.
For the citrus fruit, supreme the segments and discard the core.
Scoop the avocado out of its peel and discard the pit. Lay the avocado out on a cutting board. Season with a squeeze of lemon juice and a few pinches of salt. Cut into large chunks.
For the jicama, peel, then shave very thin on a mandolin. Stack up the jicama slices and cut to roughly 1″ by ½″ tiles.
Toss 2 c. cut jicama with ¼ c. of the vinaigrette and scatter across the center of 4 chilled plates.
Scatter a few chunks of each type of citrus over the jicama. Repeat with the avocado chunks, creating a colorful mosaic with the citrus.
Transfer one piece of cooked cod to each plate, stacking it atop the center of the mosaic. Drizzle the resting juices over the top of the fish. Vigorously whisk or stir the vinaigrette, then drizzle 2 tbsp. over each plate, dressing the avocado and citrus, as well as the fish. Sprinkle the chopped pepitas and chopped cilantro over the entire plate to garnish.
Ingredient availability varies by location*