Caramelized Fennel, Onion & Kale Toasted Cheese Sandwich Recipe

olive oil

kosher or sea salt

fennel bulb (thin wedge cut.)

medium sweet yellow onion (thinly sliced)

medium-large kale leaves. Washed (stemmed, 1/4" width slices)

butter

slices Wisconsin extra sharp cheddar cheese (4-6 oz.)

slices bread of your choice