Bring a large pot of water to a boil. Add cauliflower florets and cook for 3–5 minutes, until just fork-tender. Drain immediately and rinse with cold water to stop the cooking process. Pat dry and set aside.

In a small bowl, whisk together olive oil, sesame oil, parsley, cayenne pepper sauce, garlic, ketchup, chili paste, salt, pepper, and lemon juice.

Pour the marinade over the cauliflower in a large bowl. Toss to coat evenly. Marinate for 30 minutes. Reserve about 1/4 cup of the marinade for basting.

Preheat a lightly oiled grill pan over medium-high heat. Place the cauliflower on the pan and cook for 5–7 minutes, turning occasionally, and brushing with the reserved marinade, until lightly charred and heated through.

Remove from heat and serve warm or at room temperature.