Soak yellow split peas in boiling water for 15 minutes. Drain.

Heat 2 tablespoons olive oil in a large pot over medium-high heat. Saute onion and garlic until softened, about 5 minutes. Add yellow split peas, thyme, water, salt, and pepper. Bring to a boil, reduce heat to low and cover the pot. Continue to simmer for 45-50 minutes or until peas are tender. Skim any foam that rises to the top.

Meanwhile, make pickled onion. Combine boiling water with vinegar, sugar, and salt, stirring until sugar is dissolved. Pour mixture over chopped red onion and let sit for at least 30 minutes or overnight.

Remove thyme and transfer cooked split peas to a blender. Add lemon juice, lemon zest, and remaining 2 tablespoons olive oil. Puree until smooth. Season dip with salt and pepper and transfer to serving bowl.

Drizzle extra virgin olive oil on top and sprinkle dip with pickled onion, capers, parsley, feta, mint, and sumac. Serve wam.