Step 1
Preheat the oven to 375 degrees F (190 degrees C).
Step 2
Bring 1 teaspoon salt and water to a boil. Stir in the fusilli and return to a boil. Cook the pasta uncovered stirring occasionally for about 6 minutes.
Step 3
Stir Swiss chard stems and chicken bouillon granules into pasta and water. Continue cooking until pasta has cooked through but is still slightly firm about 6 more minutes. Reserve 1 cup of the cooking liquid. Drain pasta and chard stems.
Step 4
Heat a large skillet over medium-high heat. Cook sausage links until evenly browned and no longer pink in the center. Transfer sausage to a plate and slice.
Step 5
Heat butter and red pepper flakes over medium heat in the skillet used to cook sausage; cook and stir onion and garlic in butter until tender and onion is translucent about 5 minutes.
Step 6
Stir sliced Swiss chard leaves and balsamic vinegar into onion mixture and cook stirring occasionally until chard leaves are tender about 5 minutes.
Step 7
Mix kidney beans and tomato into chard leaf and onion mixture; continue to cook for 3 more minutes.
Step 8
Stir pasta chard stems and 1/2 of the reserved cooking liquid into the vegetables. Season with salt and black pepper. If the sauce becomes too dry add remaining cooking liquid.
Step 9
Transfer pasta mixture to a large baking dish.
Step 9
Arrange sliced sausage and crumbled feta cheese atop pasta pressing the mixture down.