Black Beans, Corn & Zucchini

1 can black beans
1 can corn
1 average size zucchini - sliced long ways into fourths and then crosswise into small pieces
1/2 c frozen onion
1 TB garlic
1 TB olive oil
1 TB ground cumin
1 tsp southwest spice blend
lime juice
salt

Saute onions and garlic in olive oil until they start to brown
add zucchini
cook until zucchini is tender
add corn and beans
heat through
add salt & lime juice to taste