Place green pepper slices in a large wide-mouth jar or bowl. Place sugar and salt in a separate bowl and add 2/3 cup boiled water; stir until sugar and salt are dissolved. Stir in cider vinegar. Let cool for a few minutes and then add vinegar mixture to peppers. Cover and chill for at least 4 hours or up to several days.
Cook lentils in a large saucepan of simmering, salted water until they are tender but still retain their shape, about 25 minutes. Drain, rinse under cold running water, and drain well again.
Bring 2 1/2 cups water to a boil in a saucepan. Add freekeh and a couple pinches of salt. Reduce heat to medium/low and simmer covered until grains are tender, about 25 minutes. Drain any excess water.
To make the dressing, blend together olive oil, water, zucchini, lemon juice, parsley, scallions, jalapeño, garlic, tahini, honey, and salt until smooth.
To serve, spread hummus on serving plates and scatter on lentils, arugula, freekeh, cucumber, avocado, and sunflower seeds. Drizzle on dressing and garnish with microgreens if using.