My guy's dad has been through two rounds of chemo and two stem cell transplants, and the one thing I know he complained about with the treatment was the impact it had on his ability to taste--everything tastes more bitter. He really enjoyed foods that were super-salty or spicy.
If your friend likes it spicy, maybe include elements for tortilla soup? (If the friend isn't a fan of too much heat, you can omit the jalapeno; the chipotle adds enough smoky heat.)
Tortilla Soup "Base"
2 tomatoes, cored and quartered
1/2 onion, halved
2 garlic cloves
1/2 jalapeno
1 chipotle chile in adobo, plus up to 1 tbsp adobo sauce
1 tbsp. vegetable oil
pinch of salt
Puree tomatoes, onion, garlic, jalapeno, chipotle and adobo in food processor until smooth. Heat oil in Dutch oven over high heat until shimmering; add tomato/onion puree and salt and cook, stirring frequently, until mixture has darkened in color, anywhere from 10-20 minutes (the longer you cook it, the more concentrated the heat/flavor).
You can freeze the "base" in ice cube trays, and use one cube per serving. When ready to serve, drop a cube into broth. Add cooked shredded chicken and simmer until heated through. Serve with tortilla strips, avocado, crema, chopped onions...you name it.