Melt butter in the pan, over medium heat, and add flour, stir in broth. Cook until it thickens, stirring constantly. Slowly add the yogurt, curry powder, lemon juice, salt and pepper. Once finished, keep sauce warm while preparing the noodles.
Boil the noodles until they are tender. Drain water, and reserve. Using a sauté pan, over medium-high heat, sauté minced garlic in olive oil until golden brown. Add summer squash, snow peas, and cook until vegetables are tender. Add pasta and mix with vegetables. Then toss in yogurt curry sauce before serving.