PREPARE THE DRESSING: In a large bowl, combine the Fresno pepper, white parts of the scallion, rose essence, thyme, lemon juice, salt, and black pepper. While mixing, drizzle in the oil until well combined and emulsified. Taste to check for salt and add more if necessary. Add the watermelon cubes and toss to coat thoroughly. Set aside and let the dressing seep in for 10 minutes.

MAKE THE CREMA: Place the sour cream, tahini paste, lemon zest, lemon juice, salt, and pepper in a food processor or blender. Blend until very smooth with no visible lumps. If the mixture is very thick and grainy, add 1 to 3 tablespoons of water and blend until it becomes a creamy paste, similar to the consistency of a smooth cream cheese.

PLATE IT UP: On a large serving dish, spread the crema in a thick layer. Then top with the watermelon salad. Garnish with the mint leaves and green parts of the scallion. Serve immediately. If traveling, pack the dressed watermelon salad separate from the crema.