Gluten Free Slow Cooker Vegetarian Meal

1 1/2 cups chopped onion

1 cup (1/4-inch-thick) slices carrot

1 tablespoon curry powder

1 teaspoon brown sugar

1 teaspoon grated peeled fresh ginger

2 garlic cloves, minced

1 serrano chile, seeded and minced

3 cups cooked chickpeas (garbanzo beans)

1 1/2 cups cubed peeled baking potato

1 cup diced green bell pepper

1 cup (1-inch) cut green beans

1/2 teaspoon salt

1/4 teaspoon black pepper

1/8 teaspoon ground red pepper

1 (14.5-ounce) can diced tomatoes, undrained

1 (14-ounce) can vegetable broth

3 cups fresh baby spinach

1 cup light coconut milk
6 lemon wedges