Chicken-Spinach Salad with Avocado Chili Cilantro Dressing

small avocado

shallot, peeled and sliced, divided (half for dressing, half for salad)

red Fresno chili, top removed sliced, divided (half for dressing, half for salad)

green onions, sliced, divided (half for dressing, half for salad)

lime, juiced

bunch of cilantro

mayonnaise

white sugar (optional)

Salt and pepper

boneless, skinless chicken thighs

grapeseed oil

spinach, packed

yellow tomato, sliced ¼ inch thick